120 lines
2.6 KiB
C++
120 lines
2.6 KiB
C++
/*
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Formatting library for C++ - string utilities
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Copyright (c) 2012 - 2016, Victor Zverovich
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All rights reserved.
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For the license information refer to format.h.
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*/
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#ifndef FMT_STRING_H_
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#define FMT_STRING_H_
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#include "fmt/format.h"
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namespace fmt {
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namespace internal {
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// A buffer that stores data in ``std::string``.
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template <typename Char>
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class StringBuffer : public Buffer<Char> {
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private:
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std::basic_string<Char> data_;
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protected:
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virtual void grow(std::size_t size) {
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data_.resize(size);
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this->ptr_ = &data_[0];
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this->capacity_ = size;
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}
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public:
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// Moves the data to ``str`` clearing the buffer.
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void move_to(std::basic_string<Char> &str) {
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data_.resize(this->size_);
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str.swap(data_);
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this->capacity_ = this->size_ = 0;
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this->ptr_ = 0;
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}
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};
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} // namespace internal
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/**
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\rst
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This class template provides operations for formatting and writing data
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into a character stream. The output is stored in ``std::string`` that grows
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dynamically.
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You can use one of the following typedefs for common character types
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and the standard allocator:
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+---------------+----------------------------+
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| Type | Definition |
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+===============+============================+
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| StringWriter | BasicStringWriter<char> |
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+---------------+----------------------------+
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| WStringWriter | BasicStringWriter<wchar_t> |
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+---------------+----------------------------+
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**Example**::
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StringWriter out;
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out << "The answer is " << 42 << "\n";
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This will write the following output to the ``out`` object:
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.. code-block:: none
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The answer is 42
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The output can be moved to an ``std::string`` with ``out.move_to()``.
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\endrst
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*/
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template <typename Char>
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class BasicStringWriter : public BasicWriter<Char> {
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private:
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internal::StringBuffer<Char> buffer_;
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public:
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/**
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\rst
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Constructs a :class:`fmt::BasicStringWriter` object.
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\endrst
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*/
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BasicStringWriter() : BasicWriter<Char>(buffer_) {}
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/**
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\rst
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Moves the buffer content to *str* clearing the buffer.
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\endrst
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*/
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void move_to(std::basic_string<Char> &str) {
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buffer_.move_to(str);
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}
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};
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typedef BasicStringWriter<char> StringWriter;
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typedef BasicStringWriter<wchar_t> WStringWriter;
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/**
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\rst
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Converts *value* to ``std::string`` using the default format for type *T*.
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**Example**::
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#include "fmt/string.h"
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std::string answer = fmt::to_string(42);
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\endrst
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*/
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template <typename T>
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std::string to_string(const T &value) {
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fmt::MemoryWriter w;
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w << value;
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return w.str();
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}
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}
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#endif // FMT_STRING_H_
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