Problem:
- gcc-8 gives the following error when compiling this function on all
standards:
test/std-format-test.cc: In member function 'constexpr auto std::formatter<S>::parse(std::format_parse_context&)':
test/std-format-test.cc:112:17: error: call to non-'constexpr' function 'int isdigit(int)'
if (!isdigit(c) || (++iter, get_char()) != '}')
~~~~~~~^~~
Solution:
- Write a `constexpr` version of `isdigit` for use in this function.
Co-authored-by: Jonathan Gopel <jgopel@quantlab.com>
* eliminate one case where basic_print_context would copy a string into a fmt::basic_memory_buffer character by character instead of using fmt::basic_memory_buffer::append
* use detail::write instead of re-implementing it
* use to_unsigned to avoid signedness conversion warnings
Problem:
- On Apple clang version 11.0.3 (clang-1103.0.32.62) in C++17 and C++20
mode, clang 11.0.0 in C++17 and C++20 mode, and clang 9.0.1 in C++17
mode, the following error is generated:
In file included from test/compile-test.cc:16:
include/fmt/compile.h:518:25: error: implicit conversion changes signedness: 'long' to 'unsigned long' [-Werror,-Wsign-conversion]
return {f, pos + (end - str.data()) + 1, ctx.next_arg_id()};
~ ~~~~^~~~~~~~~~~~
include/fmt/compile.h:538:31: note: in instantiation of function template specialization
'fmt::v7::detail::parse_specs<int, char>' requested here
constexpr auto result = parse_specs<id_type>(str, POS + 2, ID);
^
include/fmt/compile.h:569:17: note: in instantiation of function template specialization
'fmt::v7::detail::compile_format_string<fmt::v7::detail::type_list<int>, 0, 0, FMT_COMPILE_STRING>' requested here
detail::compile_format_string<detail::type_list<Args...>, 0, 0>(
^
include/fmt/compile.h:648:37: note: in instantiation of function template specialization
'fmt::v7::detail::compile<int, FMT_COMPILE_STRING, 0>' requested here
constexpr auto compiled = detail::compile<Args...>(S());
^
test/compile-test.cc:140:24: note: in instantiation of function template specialization
'fmt::v7::format<FMT_COMPILE_STRING, int, 0>' requested here
EXPECT_EQ("42", fmt::format(FMT_COMPILE("{:x}"), 0x42));
^
In file included from test/compile-test.cc:16:
include/fmt/compile.h:518:25: error: implicit conversion changes signedness: 'long' to 'unsigned long' [-Werror,-Wsign-conversion]
return {f, pos + (end - str.data()) + 1, ctx.next_arg_id()};
~ ~~~~^~~~~~~~~~~~
include/fmt/compile.h:538:31: note: in instantiation of function template specialization
'fmt::v7::detail::parse_specs<char [4], char>' requested here
constexpr auto result = parse_specs<id_type>(str, POS + 2, ID);
^
include/fmt/compile.h:494:27: note: in instantiation of function template specialization
'fmt::v7::detail::compile_format_string<fmt::v7::detail::type_list<int, int, char const (&)[4], int>, 5, 2, FMT_COMPILE_STRING>'
requested here
constexpr auto tail = compile_format_string<Args, POS, ID>(format_str);
^
include/fmt/compile.h:539:14: note: in instantiation of function template specialization
'fmt::v7::detail::parse_tail<fmt::v7::detail::type_list<int, int, char const (&)[4], int>, 5, 2, fmt::v7::detail::spec_field<char, int, 0>, FMT_COMPILE_STRING>' requested here
return parse_tail<Args, result.end, result.next_arg_id>(
^
include/fmt/compile.h:569:17: note: in instantiation of function template specialization
'fmt::v7::detail::compile_format_string<fmt::v7::detail::type_list<int, int, char const (&)[4], int>, 0, 0, FMT_COMPILE_STRING>'
requested here
detail::compile_format_string<detail::type_list<Args...>, 0, 0>(
^
include/fmt/compile.h:648:37: note: in instantiation of function template specialization
'fmt::v7::detail::compile<int, int, char const (&)[4], int, FMT_COMPILE_STRING, 0>' requested here
constexpr auto compiled = detail::compile<Args...>(S());
^
test/compile-test.cc:145:18: note: in instantiation of function template specialization
'fmt::v7::format<FMT_COMPILE_STRING, int, int, char const (&)[4], int, 0>' requested here
fmt::format(FMT_COMPILE("{:{}}{:{}}"), 42, 4, "foo", 5));
^
2 errors generated.
Solution:
- Explicitly cast the result of the subtraction to the (unsigned) outer
type.
Co-authored-by: Jonathan Gopel <jgopel@quantlab.com>
Problem:
- gcc-10 is generating the following warning at all standards:
test/format-test.cc: In member function 'virtual void UtilTest_BitCast_Test::TestBody()':
test/format-test.cc:108:42: error: useless cast to type 'uint64_t' {aka 'long long unsigned int'} [-Werror=useless-cast]
108 | s = fmt::detail::bit_cast<uint32_pair>(uint64_t(~0ull));
| ^~~~~~~~~~~~~~~
- gcc-8 is generating the following warning at all standards:
test/format-test.cc: In member function 'virtual void UtilTest_BitCast_Test::TestBody()':
test/format-test.cc:108:56: error: useless cast to type 'uint64_t' {aka 'long long unsigned int'} [-Werror=useless-cast]
s = fmt::detail::bit_cast<uint32_pair>(uint64_t(~0ull));
^
Solution:
- Cast 0 to a 64 unsigned bit int and then invert.
Co-authored-by: Jonathan Gopel <jgopel@quantlab.com>
Problem:
- The version of clang to use is specified only as `clang++`. This is
inconsistent with the specifications for gcc and exposed to unexpected
failure if the default changes.
Solution:
- Specify the exact version of clang to use. I chose `clang++-9` as that
is the version that `clang++` is currently resolving to.
Co-authored-by: Jonathan Gopel <jgopel@quantlab.com>
