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fmtlegacy/include/fmt/core.h
Victor Zverovich 2d71d7e030 Add a simple format string compilation API
2020-06-12 08:37:15 -07:00

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// Formatting library for C++ - the core API
//
// Copyright (c) 2012 - present, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.
#ifndef FMT_CORE_H_
#define FMT_CORE_H_
#include <cstdio> // std::FILE
#include <cstring>
#include <functional>
#include <iterator>
#include <memory>
#include <string>
#include <type_traits>
#include <vector>
// The fmt library version in the form major * 10000 + minor * 100 + patch.
#define FMT_VERSION 60202
#ifdef __clang__
# define FMT_CLANG_VERSION (__clang_major__ * 100 + __clang_minor__)
#else
# define FMT_CLANG_VERSION 0
#endif
#if defined(__GNUC__) && !defined(__clang__)
# define FMT_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
#else
# define FMT_GCC_VERSION 0
#endif
#if defined(__INTEL_COMPILER)
# define FMT_ICC_VERSION __INTEL_COMPILER
#else
# define FMT_ICC_VERSION 0
#endif
#if __cplusplus >= 201103L || defined(__GXX_EXPERIMENTAL_CXX0X__)
# define FMT_HAS_GXX_CXX11 FMT_GCC_VERSION
#else
# define FMT_HAS_GXX_CXX11 0
#endif
#ifdef __NVCC__
# define FMT_NVCC __NVCC__
#else
# define FMT_NVCC 0
#endif
#ifdef _MSC_VER
# define FMT_MSC_VER _MSC_VER
# define FMT_SUPPRESS_MSC_WARNING(n) __pragma(warning(suppress : n))
#else
# define FMT_MSC_VER 0
# define FMT_SUPPRESS_MSC_WARNING(n)
#endif
#ifdef __has_feature
# define FMT_HAS_FEATURE(x) __has_feature(x)
#else
# define FMT_HAS_FEATURE(x) 0
#endif
#if defined(__has_include) && !defined(__INTELLISENSE__) && \
!(FMT_ICC_VERSION && FMT_ICC_VERSION < 1600)
# define FMT_HAS_INCLUDE(x) __has_include(x)
#else
# define FMT_HAS_INCLUDE(x) 0
#endif
#ifdef __has_cpp_attribute
# define FMT_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x)
#else
# define FMT_HAS_CPP_ATTRIBUTE(x) 0
#endif
#define FMT_HAS_CPP14_ATTRIBUTE(attribute) \
(__cplusplus >= 201402L && FMT_HAS_CPP_ATTRIBUTE(attribute))
#define FMT_HAS_CPP17_ATTRIBUTE(attribute) \
(__cplusplus >= 201703L && FMT_HAS_CPP_ATTRIBUTE(attribute))
// Check if relaxed C++14 constexpr is supported.
// GCC doesn't allow throw in constexpr until version 6 (bug 67371).
#ifndef FMT_USE_CONSTEXPR
# define FMT_USE_CONSTEXPR \
(FMT_HAS_FEATURE(cxx_relaxed_constexpr) || FMT_MSC_VER >= 1910 || \
(FMT_GCC_VERSION >= 600 && __cplusplus >= 201402L)) && \
!FMT_NVCC && !FMT_ICC_VERSION
#endif
#if FMT_USE_CONSTEXPR
# define FMT_CONSTEXPR constexpr
# define FMT_CONSTEXPR_DECL constexpr
#else
# define FMT_CONSTEXPR inline
# define FMT_CONSTEXPR_DECL
#endif
#ifndef FMT_OVERRIDE
# if FMT_HAS_FEATURE(cxx_override) || \
(FMT_GCC_VERSION >= 408 && FMT_HAS_GXX_CXX11) || FMT_MSC_VER >= 1900
# define FMT_OVERRIDE override
# else
# define FMT_OVERRIDE
# endif
#endif
// Check if exceptions are disabled.
#ifndef FMT_EXCEPTIONS
# if (defined(__GNUC__) && !defined(__EXCEPTIONS)) || \
FMT_MSC_VER && !_HAS_EXCEPTIONS
# define FMT_EXCEPTIONS 0
# else
# define FMT_EXCEPTIONS 1
# endif
#endif
// Define FMT_USE_NOEXCEPT to make fmt use noexcept (C++11 feature).
#ifndef FMT_USE_NOEXCEPT
# define FMT_USE_NOEXCEPT 0
#endif
#if FMT_USE_NOEXCEPT || FMT_HAS_FEATURE(cxx_noexcept) || \
(FMT_GCC_VERSION >= 408 && FMT_HAS_GXX_CXX11) || FMT_MSC_VER >= 1900
# define FMT_DETECTED_NOEXCEPT noexcept
# define FMT_HAS_CXX11_NOEXCEPT 1
#else
# define FMT_DETECTED_NOEXCEPT throw()
# define FMT_HAS_CXX11_NOEXCEPT 0
#endif
#ifndef FMT_NOEXCEPT
# if FMT_EXCEPTIONS || FMT_HAS_CXX11_NOEXCEPT
# define FMT_NOEXCEPT FMT_DETECTED_NOEXCEPT
# else
# define FMT_NOEXCEPT
# endif
#endif
// [[noreturn]] is disabled on MSVC and NVCC because of bogus unreachable code
// warnings.
#if FMT_EXCEPTIONS && FMT_HAS_CPP_ATTRIBUTE(noreturn) && !FMT_MSC_VER && \
!FMT_NVCC
# define FMT_NORETURN [[noreturn]]
#else
# define FMT_NORETURN
#endif
#ifndef FMT_DEPRECATED
# if FMT_HAS_CPP14_ATTRIBUTE(deprecated) || FMT_MSC_VER >= 1900
# define FMT_DEPRECATED [[deprecated]]
# else
# if defined(__GNUC__) || defined(__clang__)
# define FMT_DEPRECATED __attribute__((deprecated))
# elif FMT_MSC_VER
# define FMT_DEPRECATED __declspec(deprecated)
# else
# define FMT_DEPRECATED /* deprecated */
# endif
# endif
#endif
// Workaround broken [[deprecated]] in the Intel, PGI and NVCC compilers.
#if FMT_ICC_VERSION || defined(__PGI) || FMT_NVCC
# define FMT_DEPRECATED_ALIAS
#else
# define FMT_DEPRECATED_ALIAS FMT_DEPRECATED
#endif
#ifndef FMT_INLINE
# if FMT_GCC_VERSION || FMT_CLANG_VERSION
# define FMT_INLINE inline __attribute__((always_inline))
# else
# define FMT_INLINE inline
# endif
#endif
#ifndef FMT_BEGIN_NAMESPACE
# if FMT_HAS_FEATURE(cxx_inline_namespaces) || FMT_GCC_VERSION >= 404 || \
FMT_MSC_VER >= 1900
# define FMT_INLINE_NAMESPACE inline namespace
# define FMT_END_NAMESPACE \
} \
}
# else
# define FMT_INLINE_NAMESPACE namespace
# define FMT_END_NAMESPACE \
} \
using namespace v6; \
}
# endif
# define FMT_BEGIN_NAMESPACE \
namespace fmt { \
FMT_INLINE_NAMESPACE v6 {
#endif
#if !defined(FMT_HEADER_ONLY) && defined(_WIN32)
# define FMT_CLASS_API FMT_SUPPRESS_MSC_WARNING(4275)
# ifdef FMT_EXPORT
# define FMT_API __declspec(dllexport)
# define FMT_EXTERN_TEMPLATE_API FMT_API
# elif defined(FMT_SHARED)
# define FMT_API __declspec(dllimport)
# define FMT_EXTERN_TEMPLATE_API FMT_API
# endif
#else
# define FMT_CLASS_API
#endif
#ifndef FMT_API
# if FMT_GCC_VERSION || FMT_CLANG_VERSION
# define FMT_API __attribute__((visibility("default")))
# define FMT_EXTERN_TEMPLATE_API FMT_API
# define FMT_INSTANTIATION_DEF_API
# else
# define FMT_API
# endif
#endif
#ifndef FMT_EXTERN_TEMPLATE_API
# define FMT_EXTERN_TEMPLATE_API
#endif
#ifndef FMT_INSTANTIATION_DEF_API
# define FMT_INSTANTIATION_DEF_API FMT_API
#endif
#ifndef FMT_HEADER_ONLY
# define FMT_EXTERN extern
#else
# define FMT_EXTERN
#endif
// libc++ supports string_view in pre-c++17.
#if (FMT_HAS_INCLUDE(<string_view>) && \
(__cplusplus > 201402L || defined(_LIBCPP_VERSION))) || \
(defined(_MSVC_LANG) && _MSVC_LANG > 201402L && _MSC_VER >= 1910)
# include <string_view>
# define FMT_USE_STRING_VIEW
#elif FMT_HAS_INCLUDE("experimental/string_view") && __cplusplus >= 201402L
# include <experimental/string_view>
# define FMT_USE_EXPERIMENTAL_STRING_VIEW
#endif
#ifndef FMT_UNICODE
# define FMT_UNICODE !FMT_MSC_VER
#endif
#if FMT_UNICODE && FMT_MSC_VER
# pragma execution_character_set("utf-8")
#endif
FMT_BEGIN_NAMESPACE
// Implementations of enable_if_t and other metafunctions for older systems.
template <bool B, class T = void>
using enable_if_t = typename std::enable_if<B, T>::type;
template <bool B, class T, class F>
using conditional_t = typename std::conditional<B, T, F>::type;
template <bool B> using bool_constant = std::integral_constant<bool, B>;
template <typename T>
using remove_reference_t = typename std::remove_reference<T>::type;
template <typename T>
using remove_const_t = typename std::remove_const<T>::type;
template <typename T>
using remove_cvref_t = typename std::remove_cv<remove_reference_t<T>>::type;
template <typename T> struct type_identity { using type = T; };
template <typename T> using type_identity_t = typename type_identity<T>::type;
struct monostate {};
// An enable_if helper to be used in template parameters which results in much
// shorter symbols: https://godbolt.org/z/sWw4vP. Extra parentheses are needed
// to workaround a bug in MSVC 2019 (see #1140 and #1186).
#define FMT_ENABLE_IF(...) enable_if_t<(__VA_ARGS__), int> = 0
namespace detail {
// A helper function to suppress bogus "conditional expression is constant"
// warnings.
template <typename T> constexpr T const_check(T value) { return value; }
FMT_NORETURN FMT_API void assert_fail(const char* file, int line,
const char* message);
#ifndef FMT_ASSERT
# ifdef NDEBUG
// FMT_ASSERT is not empty to avoid -Werror=empty-body.
# define FMT_ASSERT(condition, message) ((void)0)
# else
# define FMT_ASSERT(condition, message) \
((condition) /* void() fails with -Winvalid-constexpr on clang 4.0.1 */ \
? (void)0 \
: ::fmt::detail::assert_fail(__FILE__, __LINE__, (message)))
# endif
#endif
#if defined(FMT_USE_STRING_VIEW)
template <typename Char> using std_string_view = std::basic_string_view<Char>;
#elif defined(FMT_USE_EXPERIMENTAL_STRING_VIEW)
template <typename Char>
using std_string_view = std::experimental::basic_string_view<Char>;
#else
template <typename T> struct std_string_view {};
#endif
#ifdef FMT_USE_INT128
// Do nothing.
#elif defined(__SIZEOF_INT128__) && !FMT_NVCC
# define FMT_USE_INT128 1
using int128_t = __int128_t;
using uint128_t = __uint128_t;
#else
# define FMT_USE_INT128 0
#endif
#if !FMT_USE_INT128
struct int128_t {};
struct uint128_t {};
#endif
// Casts a nonnegative integer to unsigned.
template <typename Int>
FMT_CONSTEXPR typename std::make_unsigned<Int>::type to_unsigned(Int value) {
FMT_ASSERT(value >= 0, "negative value");
return static_cast<typename std::make_unsigned<Int>::type>(value);
}
FMT_SUPPRESS_MSC_WARNING(4566) constexpr unsigned char micro[] = "\u00B5";
template <typename Char> constexpr bool is_unicode() {
return FMT_UNICODE || sizeof(Char) != 1 ||
(sizeof(micro) == 3 && micro[0] == 0xC2 && micro[1] == 0xB5);
}
#ifdef __cpp_char8_t
using char8_type = char8_t;
#else
enum char8_type : unsigned char {};
#endif
} // namespace detail
namespace internal = detail; // DEPRECATED
/**
An implementation of ``std::basic_string_view`` for pre-C++17. It provides a
subset of the API. ``fmt::basic_string_view`` is used for format strings even
if ``std::string_view`` is available to prevent issues when a library is
compiled with a different ``-std`` option than the client code (which is not
recommended).
*/
template <typename Char> class basic_string_view {
private:
const Char* data_;
size_t size_;
public:
using value_type = Char;
using iterator = const Char*;
constexpr basic_string_view() FMT_NOEXCEPT : data_(nullptr), size_(0) {}
/** Constructs a string reference object from a C string and a size. */
constexpr basic_string_view(const Char* s, size_t count) FMT_NOEXCEPT
: data_(s),
size_(count) {}
/**
\rst
Constructs a string reference object from a C string computing
the size with ``std::char_traits<Char>::length``.
\endrst
*/
#if __cplusplus >= 201703L // C++17's char_traits::length() is constexpr.
FMT_CONSTEXPR
#endif
basic_string_view(const Char* s)
: data_(s), size_(std::char_traits<Char>::length(s)) {}
/** Constructs a string reference from a ``std::basic_string`` object. */
template <typename Traits, typename Alloc>
FMT_CONSTEXPR basic_string_view(
const std::basic_string<Char, Traits, Alloc>& s) FMT_NOEXCEPT
: data_(s.data()),
size_(s.size()) {}
template <typename S, FMT_ENABLE_IF(std::is_same<
S, detail::std_string_view<Char>>::value)>
FMT_CONSTEXPR basic_string_view(S s) FMT_NOEXCEPT : data_(s.data()),
size_(s.size()) {}
/** Returns a pointer to the string data. */
constexpr const Char* data() const { return data_; }
/** Returns the string size. */
constexpr size_t size() const { return size_; }
constexpr iterator begin() const { return data_; }
constexpr iterator end() const { return data_ + size_; }
constexpr const Char& operator[](size_t pos) const { return data_[pos]; }
FMT_CONSTEXPR void remove_prefix(size_t n) {
data_ += n;
size_ -= n;
}
// Lexicographically compare this string reference to other.
int compare(basic_string_view other) const {
size_t str_size = size_ < other.size_ ? size_ : other.size_;
int result = std::char_traits<Char>::compare(data_, other.data_, str_size);
if (result == 0)
result = size_ == other.size_ ? 0 : (size_ < other.size_ ? -1 : 1);
return result;
}
friend bool operator==(basic_string_view lhs, basic_string_view rhs) {
return lhs.compare(rhs) == 0;
}
friend bool operator!=(basic_string_view lhs, basic_string_view rhs) {
return lhs.compare(rhs) != 0;
}
friend bool operator<(basic_string_view lhs, basic_string_view rhs) {
return lhs.compare(rhs) < 0;
}
friend bool operator<=(basic_string_view lhs, basic_string_view rhs) {
return lhs.compare(rhs) <= 0;
}
friend bool operator>(basic_string_view lhs, basic_string_view rhs) {
return lhs.compare(rhs) > 0;
}
friend bool operator>=(basic_string_view lhs, basic_string_view rhs) {
return lhs.compare(rhs) >= 0;
}
};
using string_view = basic_string_view<char>;
using wstring_view = basic_string_view<wchar_t>;
/** Specifies if ``T`` is a character type. Can be specialized by users. */
template <typename T> struct is_char : std::false_type {};
template <> struct is_char<char> : std::true_type {};
template <> struct is_char<wchar_t> : std::true_type {};
template <> struct is_char<detail::char8_type> : std::true_type {};
template <> struct is_char<char16_t> : std::true_type {};
template <> struct is_char<char32_t> : std::true_type {};
/**
\rst
Returns a string view of `s`. In order to add custom string type support to
{fmt} provide an overload of `to_string_view` for it in the same namespace as
the type for the argument-dependent lookup to work.
**Example**::
namespace my_ns {
inline string_view to_string_view(const my_string& s) {
return {s.data(), s.length()};
}
}
std::string message = fmt::format(my_string("The answer is {}"), 42);
\endrst
*/
template <typename Char, FMT_ENABLE_IF(is_char<Char>::value)>
inline basic_string_view<Char> to_string_view(const Char* s) {
return s;
}
template <typename Char, typename Traits, typename Alloc>
inline basic_string_view<Char> to_string_view(
const std::basic_string<Char, Traits, Alloc>& s) {
return s;
}
template <typename Char>
inline basic_string_view<Char> to_string_view(basic_string_view<Char> s) {
return s;
}
template <typename Char,
FMT_ENABLE_IF(!std::is_empty<detail::std_string_view<Char>>::value)>
inline basic_string_view<Char> to_string_view(detail::std_string_view<Char> s) {
return s;
}
// A base class for compile-time strings. It is defined in the fmt namespace to
// make formatting functions visible via ADL, e.g. format(FMT_STRING("{}"), 42).
struct compile_string {};
template <typename S>
struct is_compile_string : std::is_base_of<compile_string, S> {};
template <typename S, FMT_ENABLE_IF(is_compile_string<S>::value)>
constexpr basic_string_view<typename S::char_type> to_string_view(const S& s) {
return s;
}
namespace detail {
void to_string_view(...);
using fmt::v6::to_string_view;
// Specifies whether S is a string type convertible to fmt::basic_string_view.
// It should be a constexpr function but MSVC 2017 fails to compile it in
// enable_if and MSVC 2015 fails to compile it as an alias template.
template <typename S>
struct is_string : std::is_class<decltype(to_string_view(std::declval<S>()))> {
};
template <typename S, typename = void> struct char_t_impl {};
template <typename S> struct char_t_impl<S, enable_if_t<is_string<S>::value>> {
using result = decltype(to_string_view(std::declval<S>()));
using type = typename result::value_type;
};
struct error_handler {
constexpr error_handler() = default;
constexpr error_handler(const error_handler&) = default;
// This function is intentionally not constexpr to give a compile-time error.
FMT_NORETURN FMT_API void on_error(const char* message);
};
} // namespace detail
/** String's character type. */
template <typename S> using char_t = typename detail::char_t_impl<S>::type;
/**
\rst
Parsing context consisting of a format string range being parsed and an
argument counter for automatic indexing.
You can use one of the following type aliases for common character types:
+-----------------------+-------------------------------------+
| Type | Definition |
+=======================+=====================================+
| format_parse_context | basic_format_parse_context<char> |
+-----------------------+-------------------------------------+
| wformat_parse_context | basic_format_parse_context<wchar_t> |
+-----------------------+-------------------------------------+
\endrst
*/
template <typename Char, typename ErrorHandler = detail::error_handler>
class basic_format_parse_context : private ErrorHandler {
private:
basic_string_view<Char> format_str_;
int next_arg_id_;
public:
using char_type = Char;
using iterator = typename basic_string_view<Char>::iterator;
explicit constexpr basic_format_parse_context(
basic_string_view<Char> format_str, ErrorHandler eh = {})
: ErrorHandler(eh), format_str_(format_str), next_arg_id_(0) {}
/**
Returns an iterator to the beginning of the format string range being
parsed.
*/
constexpr iterator begin() const FMT_NOEXCEPT { return format_str_.begin(); }
/**
Returns an iterator past the end of the format string range being parsed.
*/
constexpr iterator end() const FMT_NOEXCEPT { return format_str_.end(); }
/** Advances the begin iterator to ``it``. */
FMT_CONSTEXPR void advance_to(iterator it) {
format_str_.remove_prefix(detail::to_unsigned(it - begin()));
}
/**
Reports an error if using the manual argument indexing; otherwise returns
the next argument index and switches to the automatic indexing.
*/
FMT_CONSTEXPR int next_arg_id() {
// Don't check if the argument id is valid to avoid overhead and because it
// will be checked during formatting anyway.
if (next_arg_id_ >= 0) return next_arg_id_++;
on_error("cannot switch from manual to automatic argument indexing");
return 0;
}
/**
Reports an error if using the automatic argument indexing; otherwise
switches to the manual indexing.
*/
FMT_CONSTEXPR void check_arg_id(int) {
if (next_arg_id_ > 0)
on_error("cannot switch from automatic to manual argument indexing");
else
next_arg_id_ = -1;
}
FMT_CONSTEXPR void check_arg_id(basic_string_view<Char>) {}
FMT_CONSTEXPR void on_error(const char* message) {
ErrorHandler::on_error(message);
}
constexpr ErrorHandler error_handler() const { return *this; }
};
using format_parse_context = basic_format_parse_context<char>;
using wformat_parse_context = basic_format_parse_context<wchar_t>;
template <typename Context> class basic_format_arg;
template <typename Context> class basic_format_args;
template <typename Context> class dynamic_format_arg_store;
// A formatter for objects of type T.
template <typename T, typename Char = char, typename Enable = void>
struct formatter {
// A deleted default constructor indicates a disabled formatter.
formatter() = delete;
};
// Specifies if T has an enabled formatter specialization. A type can be
// formattable even if it doesn't have a formatter e.g. via a conversion.
template <typename T, typename Context>
using has_formatter =
std::is_constructible<typename Context::template formatter_type<T>>;
namespace detail {
/**
\rst
A contiguous memory buffer with an optional growing ability. It is an internal
class and shouldn't be used directly, only via `~fmt::basic_memory_buffer`.
\endrst
*/
template <typename T> class buffer {
private:
T* ptr_;
size_t size_;
size_t capacity_;
protected:
// Don't initialize ptr_ since it is not accessed to save a few cycles.
FMT_SUPPRESS_MSC_WARNING(26495)
buffer(size_t sz) FMT_NOEXCEPT : size_(sz), capacity_(sz) {}
buffer(T* p = nullptr, size_t sz = 0, size_t cap = 0) FMT_NOEXCEPT
: ptr_(p),
size_(sz),
capacity_(cap) {}
/** Sets the buffer data and capacity. */
void set(T* buf_data, size_t buf_capacity) FMT_NOEXCEPT {
ptr_ = buf_data;
capacity_ = buf_capacity;
}
/** Increases the buffer capacity to hold at least *capacity* elements. */
virtual void grow(size_t capacity) = 0;
public:
using value_type = T;
using const_reference = const T&;
buffer(const buffer&) = delete;
void operator=(const buffer&) = delete;
virtual ~buffer() = default;
T* begin() FMT_NOEXCEPT { return ptr_; }
T* end() FMT_NOEXCEPT { return ptr_ + size_; }
const T* begin() const FMT_NOEXCEPT { return ptr_; }
const T* end() const FMT_NOEXCEPT { return ptr_ + size_; }
/** Returns the size of this buffer. */
size_t size() const FMT_NOEXCEPT { return size_; }
/** Returns the capacity of this buffer. */
size_t capacity() const FMT_NOEXCEPT { return capacity_; }
/** Returns a pointer to the buffer data. */
T* data() FMT_NOEXCEPT { return ptr_; }
/** Returns a pointer to the buffer data. */
const T* data() const FMT_NOEXCEPT { return ptr_; }
/**
Resizes the buffer. If T is a POD type new elements may not be initialized.
*/
void resize(size_t new_size) {
reserve(new_size);
size_ = new_size;
}
/** Clears this buffer. */
void clear() { size_ = 0; }
/** Reserves space to store at least *capacity* elements. */
void reserve(size_t new_capacity) {
if (new_capacity > capacity_) grow(new_capacity);
}
void push_back(const T& value) {
reserve(size_ + 1);
ptr_[size_++] = value;
}
/** Appends data to the end of the buffer. */
template <typename U> void append(const U* begin, const U* end);
template <typename I> T& operator[](I index) { return ptr_[index]; }
template <typename I> const T& operator[](I index) const {
return ptr_[index];
}
};
// A container-backed buffer.
template <typename Container>
class container_buffer : public buffer<typename Container::value_type> {
private:
Container& container_;
protected:
void grow(size_t capacity) FMT_OVERRIDE {
container_.resize(capacity);
this->set(&container_[0], capacity);
}
public:
explicit container_buffer(Container& c)
: buffer<typename Container::value_type>(c.size()), container_(c) {}
};
// Extracts a reference to the container from back_insert_iterator.
template <typename Container>
inline Container& get_container(std::back_insert_iterator<Container> it) {
using bi_iterator = std::back_insert_iterator<Container>;
struct accessor : bi_iterator {
accessor(bi_iterator iter) : bi_iterator(iter) {}
using bi_iterator::container;
};
return *accessor(it).container;
}
template <typename T, typename Char = char, typename Enable = void>
struct fallback_formatter {
fallback_formatter() = delete;
};
// Specifies if T has an enabled fallback_formatter specialization.
template <typename T, typename Context>
using has_fallback_formatter =
std::is_constructible<fallback_formatter<T, typename Context::char_type>>;
struct view {};
template <typename Char, typename T> struct named_arg : view {
const Char* name;
const T& value;
named_arg(const Char* n, const T& v) : name(n), value(v) {}
};
template <typename Char> struct named_arg_info {
const Char* name;
int id;
};
template <typename T, typename Char, size_t NUM_ARGS, size_t NUM_NAMED_ARGS>
struct arg_data {
// args_[0].named_args points to named_args_ to avoid bloating format_args.
T args_[1 + (NUM_ARGS != 0 ? NUM_ARGS : 1)];
named_arg_info<Char> named_args_[NUM_NAMED_ARGS];
template <typename... U>
arg_data(const U&... init) : args_{T(named_args_, NUM_NAMED_ARGS), init...} {}
arg_data(const arg_data& other) = delete;
const T* args() const { return args_ + 1; }
named_arg_info<Char>* named_args() { return named_args_; }
};
template <typename T, typename Char, size_t NUM_ARGS>
struct arg_data<T, Char, NUM_ARGS, 0> {
T args_[NUM_ARGS != 0 ? NUM_ARGS : 1];
template <typename... U>
FMT_INLINE arg_data(const U&... init) : args_{init...} {}
FMT_INLINE const T* args() const { return args_; }
FMT_INLINE std::nullptr_t named_args() { return nullptr; }
};
template <typename Char>
inline void init_named_args(named_arg_info<Char>*, int, int) {}
template <typename Char, typename T, typename... Tail>
void init_named_args(named_arg_info<Char>* named_args, int arg_count,
int named_arg_count, const T&, const Tail&... args) {
init_named_args(named_args, arg_count + 1, named_arg_count, args...);
}
template <typename Char, typename T, typename... Tail>
void init_named_args(named_arg_info<Char>* named_args, int arg_count,
int named_arg_count, const named_arg<Char, T>& arg,
const Tail&... args) {
named_args[named_arg_count++] = {arg.name, arg_count};
init_named_args(named_args, arg_count + 1, named_arg_count, args...);
}
template <typename... Args>
FMT_INLINE void init_named_args(std::nullptr_t, int, int, const Args&...) {}
template <typename T> struct is_named_arg : std::false_type {};
template <typename T, typename Char>
struct is_named_arg<named_arg<Char, T>> : std::true_type {};
template <bool B = false> constexpr size_t count() { return B ? 1 : 0; }
template <bool B1, bool B2, bool... Tail> constexpr size_t count() {
return (B1 ? 1 : 0) + count<B2, Tail...>();
}
template <typename... Args> constexpr size_t count_named_args() {
return count<is_named_arg<Args>::value...>();
}
enum class type {
none_type,
// Integer types should go first,
int_type,
uint_type,
long_long_type,
ulong_long_type,
int128_type,
uint128_type,
bool_type,
char_type,
last_integer_type = char_type,
// followed by floating-point types.
float_type,
double_type,
long_double_type,
last_numeric_type = long_double_type,
cstring_type,
string_type,
pointer_type,
custom_type
};
// Maps core type T to the corresponding type enum constant.
template <typename T, typename Char>
struct type_constant : std::integral_constant<type, type::custom_type> {};
#define FMT_TYPE_CONSTANT(Type, constant) \
template <typename Char> \
struct type_constant<Type, Char> \
: std::integral_constant<type, type::constant> {}
FMT_TYPE_CONSTANT(int, int_type);
FMT_TYPE_CONSTANT(unsigned, uint_type);
FMT_TYPE_CONSTANT(long long, long_long_type);
FMT_TYPE_CONSTANT(unsigned long long, ulong_long_type);
FMT_TYPE_CONSTANT(int128_t, int128_type);
FMT_TYPE_CONSTANT(uint128_t, uint128_type);
FMT_TYPE_CONSTANT(bool, bool_type);
FMT_TYPE_CONSTANT(Char, char_type);
FMT_TYPE_CONSTANT(float, float_type);
FMT_TYPE_CONSTANT(double, double_type);
FMT_TYPE_CONSTANT(long double, long_double_type);
FMT_TYPE_CONSTANT(const Char*, cstring_type);
FMT_TYPE_CONSTANT(basic_string_view<Char>, string_type);
FMT_TYPE_CONSTANT(const void*, pointer_type);
constexpr bool is_integral_type(type t) {
return t > type::none_type && t <= type::last_integer_type;
}
constexpr bool is_arithmetic_type(type t) {
return t > type::none_type && t <= type::last_numeric_type;
}
template <typename Char> struct string_value {
const Char* data;
size_t size;
};
template <typename Char> struct named_arg_value {
const named_arg_info<Char>* data;
size_t size;
};
template <typename Context> struct custom_value {
using parse_context = typename Context::parse_context_type;
const void* value;
void (*format)(const void* arg, parse_context& parse_ctx, Context& ctx);
};
// A formatting argument value.
template <typename Context> class value {
public:
using char_type = typename Context::char_type;
union {
int int_value;
unsigned uint_value;
long long long_long_value;
unsigned long long ulong_long_value;
int128_t int128_value;
uint128_t uint128_value;
bool bool_value;
char_type char_value;
float float_value;
double double_value;
long double long_double_value;
const void* pointer;
string_value<char_type> string;
custom_value<Context> custom;
named_arg_value<char_type> named_args;
};
constexpr FMT_INLINE value(int val = 0) : int_value(val) {}
constexpr FMT_INLINE value(unsigned val) : uint_value(val) {}
FMT_INLINE value(long long val) : long_long_value(val) {}
FMT_INLINE value(unsigned long long val) : ulong_long_value(val) {}
FMT_INLINE value(int128_t val) : int128_value(val) {}
FMT_INLINE value(uint128_t val) : uint128_value(val) {}
FMT_INLINE value(float val) : float_value(val) {}
FMT_INLINE value(double val) : double_value(val) {}
FMT_INLINE value(long double val) : long_double_value(val) {}
FMT_INLINE value(bool val) : bool_value(val) {}
FMT_INLINE value(char_type val) : char_value(val) {}
FMT_INLINE value(const char_type* val) { string.data = val; }
FMT_INLINE value(basic_string_view<char_type> val) {
string.data = val.data();
string.size = val.size();
}
FMT_INLINE value(const void* val) : pointer(val) {}
FMT_INLINE value(const named_arg_info<char_type>* args, size_t size)
: named_args{args, size} {}
template <typename T> FMT_INLINE value(const T& val) {
custom.value = &val;
// Get the formatter type through the context to allow different contexts
// have different extension points, e.g. `formatter<T>` for `format` and
// `printf_formatter<T>` for `printf`.
custom.format = format_custom_arg<
T, conditional_t<has_formatter<T, Context>::value,
typename Context::template formatter_type<T>,
fallback_formatter<T, char_type>>>;
}
private:
// Formats an argument of a custom type, such as a user-defined class.
template <typename T, typename Formatter>
static void format_custom_arg(const void* arg,
typename Context::parse_context_type& parse_ctx,
Context& ctx) {
Formatter f;
parse_ctx.advance_to(f.parse(parse_ctx));
ctx.advance_to(f.format(*static_cast<const T*>(arg), ctx));
}
};
template <typename Context, typename T>
FMT_CONSTEXPR basic_format_arg<Context> make_arg(const T& value);
// To minimize the number of types we need to deal with, long is translated
// either to int or to long long depending on its size.
enum { long_short = sizeof(long) == sizeof(int) };
using long_type = conditional_t<long_short, int, long long>;
using ulong_type = conditional_t<long_short, unsigned, unsigned long long>;
// Maps formatting arguments to core types.
template <typename Context> struct arg_mapper {
using char_type = typename Context::char_type;
FMT_CONSTEXPR int map(signed char val) { return val; }
FMT_CONSTEXPR unsigned map(unsigned char val) { return val; }
FMT_CONSTEXPR int map(short val) { return val; }
FMT_CONSTEXPR unsigned map(unsigned short val) { return val; }
FMT_CONSTEXPR int map(int val) { return val; }
FMT_CONSTEXPR unsigned map(unsigned val) { return val; }
FMT_CONSTEXPR long_type map(long val) { return val; }
FMT_CONSTEXPR ulong_type map(unsigned long val) { return val; }
FMT_CONSTEXPR long long map(long long val) { return val; }
FMT_CONSTEXPR unsigned long long map(unsigned long long val) { return val; }
FMT_CONSTEXPR int128_t map(int128_t val) { return val; }
FMT_CONSTEXPR uint128_t map(uint128_t val) { return val; }
FMT_CONSTEXPR bool map(bool val) { return val; }
template <typename T, FMT_ENABLE_IF(is_char<T>::value)>
FMT_CONSTEXPR char_type map(T val) {
static_assert(
std::is_same<T, char>::value || std::is_same<T, char_type>::value,
"mixing character types is disallowed");
return val;
}
FMT_CONSTEXPR float map(float val) { return val; }
FMT_CONSTEXPR double map(double val) { return val; }
FMT_CONSTEXPR long double map(long double val) { return val; }
FMT_CONSTEXPR const char_type* map(char_type* val) { return val; }
FMT_CONSTEXPR const char_type* map(const char_type* val) { return val; }
template <typename T, FMT_ENABLE_IF(is_string<T>::value)>
FMT_CONSTEXPR basic_string_view<char_type> map(const T& val) {
static_assert(std::is_same<char_type, char_t<T>>::value,
"mixing character types is disallowed");
return to_string_view(val);
}
template <typename T,
FMT_ENABLE_IF(
std::is_constructible<basic_string_view<char_type>, T>::value &&
!is_string<T>::value && !has_formatter<T, Context>::value &&
!has_fallback_formatter<T, Context>::value)>
FMT_CONSTEXPR basic_string_view<char_type> map(const T& val) {
return basic_string_view<char_type>(val);
}
template <
typename T,
FMT_ENABLE_IF(
std::is_constructible<std_string_view<char_type>, T>::value &&
!std::is_constructible<basic_string_view<char_type>, T>::value &&
!is_string<T>::value && !has_formatter<T, Context>::value &&
!has_fallback_formatter<T, Context>::value)>
FMT_CONSTEXPR basic_string_view<char_type> map(const T& val) {
return std_string_view<char_type>(val);
}
FMT_CONSTEXPR const char* map(const signed char* val) {
static_assert(std::is_same<char_type, char>::value, "invalid string type");
return reinterpret_cast<const char*>(val);
}
FMT_CONSTEXPR const char* map(const unsigned char* val) {
static_assert(std::is_same<char_type, char>::value, "invalid string type");
return reinterpret_cast<const char*>(val);
}
FMT_CONSTEXPR const char* map(signed char* val) {
const auto* const_val = val;
return map(const_val);
}
FMT_CONSTEXPR const char* map(unsigned char* val) {
const auto* const_val = val;
return map(const_val);
}
FMT_CONSTEXPR const void* map(void* val) { return val; }
FMT_CONSTEXPR const void* map(const void* val) { return val; }
FMT_CONSTEXPR const void* map(std::nullptr_t val) { return val; }
template <typename T> FMT_CONSTEXPR int map(const T*) {
// Formatting of arbitrary pointers is disallowed. If you want to output
// a pointer cast it to "void *" or "const void *". In particular, this
// forbids formatting of "[const] volatile char *" which is printed as bool
// by iostreams.
static_assert(!sizeof(T), "formatting of non-void pointers is disallowed");
return 0;
}
template <typename T,
FMT_ENABLE_IF(std::is_enum<T>::value &&
!has_formatter<T, Context>::value &&
!has_fallback_formatter<T, Context>::value)>
FMT_CONSTEXPR auto map(const T& val)
-> decltype(std::declval<arg_mapper>().map(
static_cast<typename std::underlying_type<T>::type>(val))) {
return map(static_cast<typename std::underlying_type<T>::type>(val));
}
template <typename T,
FMT_ENABLE_IF(!is_string<T>::value && !is_char<T>::value &&
(has_formatter<T, Context>::value ||
has_fallback_formatter<T, Context>::value))>
FMT_CONSTEXPR const T& map(const T& val) {
return val;
}
template <typename T>
FMT_CONSTEXPR auto map(const named_arg<char_type, T>& val)
-> decltype(std::declval<arg_mapper>().map(val.value)) {
return map(val.value);
}
int map(...) {
constexpr bool formattable = sizeof(Context) == 0;
static_assert(
formattable,
"Cannot format argument. To make type T formattable provide a "
"formatter<T> specialization: "
"https://fmt.dev/latest/api.html#formatting-user-defined-types");
return 0;
}
};
// A type constant after applying arg_mapper<Context>.
template <typename T, typename Context>
using mapped_type_constant =
type_constant<decltype(arg_mapper<Context>().map(std::declval<const T&>())),
typename Context::char_type>;
enum { packed_arg_bits = 4 };
// Maximum number of arguments with packed types.
enum { max_packed_args = 62 / packed_arg_bits };
enum : unsigned long long { is_unpacked_bit = 1ULL << 63 };
enum : unsigned long long { has_named_args_bit = 1ULL << 62 };
} // namespace detail
// A formatting argument. It is a trivially copyable/constructible type to
// allow storage in basic_memory_buffer.
template <typename Context> class basic_format_arg {
private:
detail::value<Context> value_;
detail::type type_;
template <typename ContextType, typename T>
friend FMT_CONSTEXPR basic_format_arg<ContextType> detail::make_arg(
const T& value);
template <typename Visitor, typename Ctx>
friend FMT_CONSTEXPR auto visit_format_arg(Visitor&& vis,
const basic_format_arg<Ctx>& arg)
-> decltype(vis(0));
friend class basic_format_args<Context>;
friend class dynamic_format_arg_store<Context>;
using char_type = typename Context::char_type;
template <typename T, typename Char, size_t NUM_ARGS, size_t NUM_NAMED_ARGS>
friend struct detail::arg_data;
basic_format_arg(const detail::named_arg_info<char_type>* args, size_t size)
: value_(args, size) {}
public:
class handle {
public:
explicit handle(detail::custom_value<Context> custom) : custom_(custom) {}
void format(typename Context::parse_context_type& parse_ctx,
Context& ctx) const {
custom_.format(custom_.value, parse_ctx, ctx);
}
private:
detail::custom_value<Context> custom_;
};
constexpr basic_format_arg() : type_(detail::type::none_type) {}
constexpr explicit operator bool() const FMT_NOEXCEPT {
return type_ != detail::type::none_type;
}
detail::type type() const { return type_; }
bool is_integral() const { return detail::is_integral_type(type_); }
bool is_arithmetic() const { return detail::is_arithmetic_type(type_); }
};
/**
\rst
Visits an argument dispatching to the appropriate visit method based on
the argument type. For example, if the argument type is ``double`` then
``vis(value)`` will be called with the value of type ``double``.
\endrst
*/
template <typename Visitor, typename Context>
FMT_CONSTEXPR_DECL FMT_INLINE auto visit_format_arg(
Visitor&& vis, const basic_format_arg<Context>& arg) -> decltype(vis(0)) {
using char_type = typename Context::char_type;
switch (arg.type_) {
case detail::type::none_type:
break;
case detail::type::int_type:
return vis(arg.value_.int_value);
case detail::type::uint_type:
return vis(arg.value_.uint_value);
case detail::type::long_long_type:
return vis(arg.value_.long_long_value);
case detail::type::ulong_long_type:
return vis(arg.value_.ulong_long_value);
#if FMT_USE_INT128
case detail::type::int128_type:
return vis(arg.value_.int128_value);
case detail::type::uint128_type:
return vis(arg.value_.uint128_value);
#else
case detail::type::int128_type:
case detail::type::uint128_type:
break;
#endif
case detail::type::bool_type:
return vis(arg.value_.bool_value);
case detail::type::char_type:
return vis(arg.value_.char_value);
case detail::type::float_type:
return vis(arg.value_.float_value);
case detail::type::double_type:
return vis(arg.value_.double_value);
case detail::type::long_double_type:
return vis(arg.value_.long_double_value);
case detail::type::cstring_type:
return vis(arg.value_.string.data);
case detail::type::string_type:
return vis(basic_string_view<char_type>(arg.value_.string.data,
arg.value_.string.size));
case detail::type::pointer_type:
return vis(arg.value_.pointer);
case detail::type::custom_type:
return vis(typename basic_format_arg<Context>::handle(arg.value_.custom));
}
return vis(monostate());
}
// Checks whether T is a container with contiguous storage.
template <typename T> struct is_contiguous : std::false_type {};
template <typename Char>
struct is_contiguous<std::basic_string<Char>> : std::true_type {};
template <typename Char>
struct is_contiguous<detail::buffer<Char>> : std::true_type {};
namespace detail {
template <typename OutputIt>
struct is_back_insert_iterator : std::false_type {};
template <typename Container>
struct is_back_insert_iterator<std::back_insert_iterator<Container>>
: std::true_type {};
template <typename OutputIt>
struct is_contiguous_back_insert_iterator : std::false_type {};
template <typename Container>
struct is_contiguous_back_insert_iterator<std::back_insert_iterator<Container>>
: is_contiguous<Container> {};
// A type-erased reference to an std::locale to avoid heavy <locale> include.
class locale_ref {
private:
const void* locale_; // A type-erased pointer to std::locale.
public:
locale_ref() : locale_(nullptr) {}
template <typename Locale> explicit locale_ref(const Locale& loc);
explicit operator bool() const FMT_NOEXCEPT { return locale_ != nullptr; }
template <typename Locale> Locale get() const;
};
template <typename> constexpr unsigned long long encode_types() { return 0; }
template <typename Context, typename Arg, typename... Args>
constexpr unsigned long long encode_types() {
return static_cast<unsigned>(mapped_type_constant<Arg, Context>::value) |
(encode_types<Context, Args...>() << packed_arg_bits);
}
template <typename Context, typename T>
FMT_CONSTEXPR basic_format_arg<Context> make_arg(const T& value) {
basic_format_arg<Context> arg;
arg.type_ = mapped_type_constant<T, Context>::value;
arg.value_ = arg_mapper<Context>().map(value);
return arg;
}
// The type template parameter is there to avoid an ODR violation when using
// a fallback formatter in one translation unit and an implicit conversion in
// another (not recommended).
template <bool IS_PACKED, typename Context, type, typename T,
FMT_ENABLE_IF(IS_PACKED)>
inline value<Context> make_arg(const T& val) {
return arg_mapper<Context>().map(val);
}
template <bool IS_PACKED, typename Context, type, typename T,
FMT_ENABLE_IF(!IS_PACKED)>
inline basic_format_arg<Context> make_arg(const T& value) {
return make_arg<Context>(value);
}
template <typename T> struct is_reference_wrapper : std::false_type {};
template <typename T>
struct is_reference_wrapper<std::reference_wrapper<T>> : std::true_type {};
template <typename T> const T& unwrap(const T& v) { return v; }
template <typename T> const T& unwrap(const std::reference_wrapper<T>& v) {
return static_cast<const T&>(v);
}
class dynamic_arg_list {
// Workaround for clang's -Wweak-vtables. Unlike for regular classes, for
// templates it doesn't complain about inability to deduce single translation
// unit for placing vtable. So storage_node_base is made a fake template.
template <typename = void> struct node {
virtual ~node() = default;
std::unique_ptr<node<>> next;
};
template <typename T> struct typed_node : node<> {
T value;
template <typename Arg>
FMT_CONSTEXPR typed_node(const Arg& arg) : value(arg) {}
template <typename Char>
FMT_CONSTEXPR typed_node(const basic_string_view<Char>& arg)
: value(arg.data(), arg.size()) {}
};
std::unique_ptr<node<>> head_;
public:
template <typename T, typename Arg> const T& push(const Arg& arg) {
auto new_node = std::unique_ptr<typed_node<T>>(new typed_node<T>(arg));
auto& value = new_node->value;
new_node->next = std::move(head_);
head_ = std::move(new_node);
return value;
}
};
} // namespace detail
// Formatting context.
template <typename OutputIt, typename Char> class basic_format_context {
public:
/** The character type for the output. */
using char_type = Char;
private:
OutputIt out_;
basic_format_args<basic_format_context> args_;
detail::locale_ref loc_;
public:
using iterator = OutputIt;
using format_arg = basic_format_arg<basic_format_context>;
using parse_context_type = basic_format_parse_context<Char>;
template <typename T> using formatter_type = formatter<T, char_type>;
basic_format_context(const basic_format_context&) = delete;
void operator=(const basic_format_context&) = delete;
/**
Constructs a ``basic_format_context`` object. References to the arguments are
stored in the object so make sure they have appropriate lifetimes.
*/
basic_format_context(OutputIt out,
basic_format_args<basic_format_context> ctx_args,
detail::locale_ref loc = detail::locale_ref())
: out_(out), args_(ctx_args), loc_(loc) {}
format_arg arg(int id) const { return args_.get(id); }
format_arg arg(basic_string_view<char_type> name) { return args_.get(name); }
int arg_id(basic_string_view<char_type> name) { return args_.get_id(name); }
const basic_format_args<basic_format_context>& args() const { return args_; }
detail::error_handler error_handler() { return {}; }
void on_error(const char* message) { error_handler().on_error(message); }
// Returns an iterator to the beginning of the output range.
iterator out() { return out_; }
// Advances the begin iterator to ``it``.
void advance_to(iterator it) {
if (!detail::is_back_insert_iterator<iterator>()) out_ = it;
}
detail::locale_ref locale() { return loc_; }
};
template <typename Char>
using buffer_context =
basic_format_context<std::back_insert_iterator<detail::buffer<Char>>, Char>;
using format_context = buffer_context<char>;
using wformat_context = buffer_context<wchar_t>;
/**
\rst
An array of references to arguments. It can be implicitly converted into
`~fmt::basic_format_args` for passing into type-erased formatting functions
such as `~fmt::vformat`.
\endrst
*/
template <typename Context, typename... Args>
class format_arg_store
#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
// Workaround a GCC template argument substitution bug.
: public basic_format_args<Context>
#endif
{
private:
static const size_t num_args = sizeof...(Args);
static const size_t num_named_args = detail::count_named_args<Args...>();
static const bool is_packed = num_args <= detail::max_packed_args;
using value_type = conditional_t<is_packed, detail::value<Context>,
basic_format_arg<Context>>;
detail::arg_data<value_type, typename Context::char_type, num_args,
num_named_args>
data_;
friend class basic_format_args<Context>;
static constexpr unsigned long long desc =
(is_packed ? detail::encode_types<Context, Args...>()
: detail::is_unpacked_bit | num_args) |
(num_named_args != 0
? static_cast<unsigned long long>(detail::has_named_args_bit)
: 0);
public:
format_arg_store(const Args&... args)
:
#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
basic_format_args<Context>(*this),
#endif
data_{detail::make_arg<
is_packed, Context,
detail::mapped_type_constant<Args, Context>::value>(args)...} {
detail::init_named_args(data_.named_args(), 0, 0, args...);
}
};
/**
\rst
Constructs an `~fmt::format_arg_store` object that contains references to
arguments and can be implicitly converted to `~fmt::format_args`. `Context`
can be omitted in which case it defaults to `~fmt::context`.
See `~fmt::arg` for lifetime considerations.
\endrst
*/
template <typename Context = format_context, typename... Args>
inline format_arg_store<Context, Args...> make_format_args(
const Args&... args) {
return {args...};
}
/**
\rst
Returns a named argument to be used in a formatting function. It should only
be used in a call to a formatting function.
**Example**::
fmt::print("Elapsed time: {s:.2f} seconds", fmt::arg("s", 1.23));
\endrst
*/
template <typename Char, typename T>
inline detail::named_arg<Char, T> arg(const Char* name, const T& arg) {
static_assert(!detail::is_named_arg<T>(), "nested named arguments");
return {name, arg};
}
/**
\rst
A dynamic version of `fmt::format_arg_store`.
It's equipped with a storage to potentially temporary objects which lifetimes
could be shorter than the format arguments object.
It can be implicitly converted into `~fmt::basic_format_args` for passing
into type-erased formatting functions such as `~fmt::vformat`.
\endrst
*/
template <typename Context>
class dynamic_format_arg_store
#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
// Workaround a GCC template argument substitution bug.
: public basic_format_args<Context>
#endif
{
private:
using char_type = typename Context::char_type;
template <typename T> struct need_copy {
static constexpr detail::type mapped_type =
detail::mapped_type_constant<T, Context>::value;
enum {
value = !(detail::is_reference_wrapper<T>::value ||
std::is_same<T, basic_string_view<char_type>>::value ||
std::is_same<T, detail::std_string_view<char_type>>::value ||
(mapped_type != detail::type::cstring_type &&
mapped_type != detail::type::string_type &&
mapped_type != detail::type::custom_type))
};
};
template <typename T>
using stored_type = conditional_t<detail::is_string<T>::value,
std::basic_string<char_type>, T>;
// Storage of basic_format_arg must be contiguous.
std::vector<basic_format_arg<Context>> data_;
std::vector<detail::named_arg_info<char_type>> named_info_;
// Storage of arguments not fitting into basic_format_arg must grow
// without relocation because items in data_ refer to it.
detail::dynamic_arg_list dynamic_args_;
friend class basic_format_args<Context>;
unsigned long long get_types() const {
return detail::is_unpacked_bit | data_.size() |
(named_info_.empty()
? 0ULL
: static_cast<unsigned long long>(detail::has_named_args_bit));
}
const basic_format_arg<Context>* data() const {
return named_info_.empty() ? data_.data() : data_.data() + 1;
}
template <typename T> void emplace_arg(const T& arg) {
data_.emplace_back(detail::make_arg<Context>(arg));
}
template <typename T>
void emplace_arg(const detail::named_arg<char_type, T>& arg) {
if (named_info_.empty()) {
constexpr const detail::named_arg_info<char_type>* zero_ptr{nullptr};
data_.insert(data_.begin(), {zero_ptr, 0});
}
data_.emplace_back(detail::make_arg<Context>(detail::unwrap(arg.value)));
auto pop_one = [](std::vector<basic_format_arg<Context>>* data) {
data->pop_back();
};
std::unique_ptr<std::vector<basic_format_arg<Context>>, decltype(pop_one)>
guard{&data_, pop_one};
named_info_.push_back({arg.name, static_cast<int>(data_.size() - 2u)});
data_[0].value_.named_args = {named_info_.data(), named_info_.size()};
guard.release();
}
public:
/**
\rst
Adds an argument into the dynamic store for later passing to a formating
function.
Note that custom types and string types (but not string views) are copied
into the store dynamically allocating memory if necessary.
**Example**::
fmt::dynamic_format_arg_store<fmt::format_context> store;
store.push_back(42);
store.push_back("abc");
store.push_back(1.5f);
std::string result = fmt::vformat("{} and {} and {}", store);
\endrst
*/
template <typename T> void push_back(const T& arg) {
if (detail::const_check(need_copy<T>::value))
emplace_arg(dynamic_args_.push<stored_type<T>>(arg));
else
emplace_arg(detail::unwrap(arg));
}
/**
\rst
Adds a reference to the argument into the dynamic store for later passing to
a formating function. Supports named arguments wrapped in
``std::reference_wrapper`` via ``std::ref()``/``std::cref()``.
**Example**::
fmt::dynamic_format_arg_store<fmt::format_context> store;
char str[] = "1234567890";
store.push_back(std::cref(str));
int a1_val{42};
auto a1 = fmt::arg("a1_", a1_val);
store.push_back(std::cref(a1));
// Changing str affects the output but only for string and custom types.
str[0] = 'X';
std::string result = fmt::vformat("{} and {a1_}");
assert(result == "X234567890 and 42");
\endrst
*/
template <typename T> void push_back(std::reference_wrapper<T> arg) {
static_assert(
detail::is_named_arg<typename std::remove_cv<T>::type>::value ||
need_copy<T>::value,
"objects of built-in types and string views are always copied");
emplace_arg(arg.get());
}
/**
Adds named argument into the dynamic store for later passing to a formating
function. ``std::reference_wrapper`` is supported to avoid copying of the
argument.
*/
template <typename T>
void push_back(const detail::named_arg<char_type, T>& arg) {
const char_type* arg_name =
dynamic_args_.push<std::basic_string<char_type>>(arg.name).c_str();
if (detail::const_check(need_copy<T>::value)) {
emplace_arg(
fmt::arg(arg_name, dynamic_args_.push<stored_type<T>>(arg.value)));
} else {
emplace_arg(fmt::arg(arg_name, arg.value));
}
}
/** Erase all elements from the store */
void clear() {
data_.clear();
named_info_.clear();
dynamic_args_ = internal::dynamic_arg_list();
}
/**
\rst
Reserves space to store at least *new_cap* arguments including
*new_cap_named* named arguments.
\endrst
*/
void reserve(size_t new_cap, size_t new_cap_named) {
FMT_ASSERT(new_cap >= new_cap_named,
"Set of arguments includes set of named arguments");
data_.reserve(new_cap);
named_info_.reserve(new_cap_named);
}
};
/**
\rst
A view of a collection of formatting arguments. To avoid lifetime issues it
should only be used as a parameter type in type-erased functions such as
``vformat``::
void vlog(string_view format_str, format_args args); // OK
format_args args = make_format_args(42); // Error: dangling reference
\endrst
*/
template <typename Context> class basic_format_args {
public:
using size_type = int;
using format_arg = basic_format_arg<Context>;
private:
// A descriptor that contains information about formatting arguments.
// If the number of arguments is less or equal to max_packed_args then
// argument types are passed in the descriptor. This reduces binary code size
// per formatting function call.
unsigned long long desc_;
union {
// If is_packed() returns true then argument values are stored in values_;
// otherwise they are stored in args_. This is done to improve cache
// locality and reduce compiled code size since storing larger objects
// may require more code (at least on x86-64) even if the same amount of
// data is actually copied to stack. It saves ~10% on the bloat test.
const detail::value<Context>* values_;
const format_arg* args_;
};
bool is_packed() const { return (desc_ & detail::is_unpacked_bit) == 0; }
bool has_named_args() const {
return (desc_ & detail::has_named_args_bit) != 0;
}
detail::type type(int index) const {
int shift = index * detail::packed_arg_bits;
unsigned int mask = (1 << detail::packed_arg_bits) - 1;
return static_cast<detail::type>((desc_ >> shift) & mask);
}
basic_format_args(unsigned long long desc,
const detail::value<Context>* values)
: desc_(desc), values_(values) {}
basic_format_args(unsigned long long desc, const format_arg* args)
: desc_(desc), args_(args) {}
public:
basic_format_args() : desc_(0) {}
/**
\rst
Constructs a `basic_format_args` object from `~fmt::format_arg_store`.
\endrst
*/
template <typename... Args>
FMT_INLINE basic_format_args(const format_arg_store<Context, Args...>& store)
: basic_format_args(store.desc, store.data_.args()) {}
/**
\rst
Constructs a `basic_format_args` object from
`~fmt::dynamic_format_arg_store`.
\endrst
*/
FMT_INLINE basic_format_args(const dynamic_format_arg_store<Context>& store)
: basic_format_args(store.get_types(), store.data()) {}
/**
\rst
Constructs a `basic_format_args` object from a dynamic set of arguments.
\endrst
*/
basic_format_args(const format_arg* args, int count)
: basic_format_args(detail::is_unpacked_bit | detail::to_unsigned(count),
args) {}
/** Returns the argument with the specified id. */
format_arg get(int id) const {
format_arg arg;
if (!is_packed()) {
if (id < max_size()) arg = args_[id];
return arg;
}
if (id >= detail::max_packed_args) return arg;
arg.type_ = type(id);
if (arg.type_ == detail::type::none_type) return arg;
arg.value_ = values_[id];
return arg;
}
template <typename Char> format_arg get(basic_string_view<Char> name) const {
int id = get_id(name);
return id >= 0 ? get(id) : format_arg();
}
template <typename Char> int get_id(basic_string_view<Char> name) const {
if (!has_named_args()) return {};
const auto& named_args =
(is_packed() ? values_[-1] : args_[-1].value_).named_args;
for (size_t i = 0; i < named_args.size; ++i) {
if (named_args.data[i].name == name) return named_args.data[i].id;
}
return -1;
}
int max_size() const {
unsigned long long max_packed = detail::max_packed_args;
return static_cast<int>(is_packed() ? max_packed
: desc_ & ~detail::is_unpacked_bit);
}
};
/** An alias to ``basic_format_args<context>``. */
// It is a separate type rather than an alias to make symbols readable.
struct format_args : basic_format_args<format_context> {
template <typename... Args>
FMT_INLINE format_args(const Args&... args) : basic_format_args(args...) {}
};
struct wformat_args : basic_format_args<wformat_context> {
using basic_format_args::basic_format_args;
};
namespace detail {
// Reports a compile-time error if S is not a valid format string.
template <typename..., typename S, FMT_ENABLE_IF(!is_compile_string<S>::value)>
FMT_INLINE void check_format_string(const S&) {
#ifdef FMT_ENFORCE_COMPILE_STRING
static_assert(is_compile_string<S>::value,
"FMT_ENFORCE_COMPILE_STRING requires all format strings to use "
"FMT_STRING.");
#endif
}
template <typename..., typename S, FMT_ENABLE_IF(is_compile_string<S>::value)>
void check_format_string(S);
template <typename... Args, typename S, typename Char = char_t<S>>
inline format_arg_store<buffer_context<Char>, remove_reference_t<Args>...>
make_args_checked(const S& format_str,
const remove_reference_t<Args>&... args) {
static_assert(count<(std::is_base_of<view, remove_reference_t<Args>>::value &&
std::is_reference<Args>::value)...>() == 0,
"passing views as lvalues is disallowed");
check_format_string<Args...>(format_str);
return {args...};
}
template <typename Char, FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
std::basic_string<Char> vformat(
basic_string_view<Char> format_str,
basic_format_args<buffer_context<type_identity_t<Char>>> args);
std::string vformat(string_view format_str, format_args args);
template <typename Char>
typename buffer_context<Char>::iterator vformat_to(
buffer<Char>& buf, basic_string_view<Char> format_str,
basic_format_args<buffer_context<type_identity_t<Char>>> args);
template <typename Char, typename Args,
FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
inline void vprint_mojibake(std::FILE*, basic_string_view<Char>, const Args&) {}
FMT_API void vprint_mojibake(std::FILE*, string_view, format_args);
#ifndef _WIN32
inline void vprint_mojibake(std::FILE*, string_view, format_args) {}
#endif
} // namespace detail
/** Formats a string and writes the output to ``out``. */
// GCC 8 and earlier cannot handle std::back_insert_iterator<Container> with
// vformat_to<ArgFormatter>(...) overload, so SFINAE on iterator type instead.
template <
typename OutputIt, typename S, typename Char = char_t<S>,
FMT_ENABLE_IF(detail::is_contiguous_back_insert_iterator<OutputIt>::value)>
OutputIt vformat_to(
OutputIt out, const S& format_str,
basic_format_args<buffer_context<type_identity_t<Char>>> args) {
auto& c = detail::get_container(out);
detail::container_buffer<remove_reference_t<decltype(c)>> buf(c);
detail::vformat_to(buf, to_string_view(format_str), args);
return out;
}
template <typename Container, typename S, typename... Args,
FMT_ENABLE_IF(
is_contiguous<Container>::value&& detail::is_string<S>::value)>
inline std::back_insert_iterator<Container> format_to(
std::back_insert_iterator<Container> out, const S& format_str,
Args&&... args) {
return vformat_to(out, to_string_view(format_str),
detail::make_args_checked<Args...>(format_str, args...));
}
template <typename S, typename Char = char_t<S>>
FMT_INLINE std::basic_string<Char> vformat(
const S& format_str,
basic_format_args<buffer_context<type_identity_t<Char>>> args) {
return detail::vformat(to_string_view(format_str), args);
}
/**
\rst
Formats arguments and returns the result as a string.
**Example**::
#include <fmt/core.h>
std::string message = fmt::format("The answer is {}", 42);
\endrst
*/
// Pass char_t as a default template parameter instead of using
// std::basic_string<char_t<S>> to reduce the symbol size.
template <typename S, typename... Args, typename Char = char_t<S>>
FMT_INLINE std::basic_string<Char> format(const S& format_str, Args&&... args) {
const auto& vargs = detail::make_args_checked<Args...>(format_str, args...);
return detail::vformat(to_string_view(format_str), vargs);
}
FMT_API void vprint(string_view, format_args);
FMT_API void vprint(std::FILE*, string_view, format_args);
/**
\rst
Formats ``args`` according to specifications in ``format_str`` and writes the
output to the file ``f``. Strings are assumed to be Unicode-encoded unless the
``FMT_UNICODE`` macro is set to 0.
**Example**::
fmt::print(stderr, "Don't {}!", "panic");
\endrst
*/
template <typename S, typename... Args, typename Char = char_t<S>>
inline void print(std::FILE* f, const S& format_str, Args&&... args) {
const auto& vargs = detail::make_args_checked<Args...>(format_str, args...);
return detail::is_unicode<Char>()
? vprint(f, to_string_view(format_str), vargs)
: detail::vprint_mojibake(f, to_string_view(format_str), vargs);
}
/**
\rst
Formats ``args`` according to specifications in ``format_str`` and writes
the output to ``stdout``. Strings are assumed to be Unicode-encoded unless
the ``FMT_UNICODE`` macro is set to 0.
**Example**::
fmt::print("Elapsed time: {0:.2f} seconds", 1.23);
\endrst
*/
template <typename S, typename... Args, typename Char = char_t<S>>
inline void print(const S& format_str, Args&&... args) {
const auto& vargs = detail::make_args_checked<Args...>(format_str, args...);
return detail::is_unicode<Char>()
? vprint(to_string_view(format_str), vargs)
: detail::vprint_mojibake(stdout, to_string_view(format_str),
vargs);
}
FMT_END_NAMESPACE
#endif // FMT_CORE_H_
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