In particular, this uses FMT_ENABLE_IF() to constrain the function to only
valid combinations of the format string and arguments. This ensures that there
is an actual error at the usage site, which puts the red squiggles on the
incorrect code, rather than inside the library.
* Fix conditional `char8_t` from `format.h` and fix `-Wunused-result` of [[no_discard]] begin() when in c++17
* Suppress `-Winconsistent-dllimport` when in clang-target-msvc
* Suppress warning _CRT_SECURE_NO_WARNINGS in MSVC and -Wdeprecated-declarations
Suppress warning _CRT_SECURE_NO_WARNINGS in MSVC and -Wdeprecated-declarations of POSIX functions in Clang target MSVC.
Those functions are used by gtest.
* Remove FMT_FUNC, mark FMT_API to export
* This translation unit includes `gtest.h` in which using something like `strncpy`
Suppress MSVC warnings from `gtest.h` included.
Warning sample:
fmt-master\test\gtest\gtest.h(2873,10): warning: 'strncpy' is deprecated: This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details. [-Wdeprecated-declarations]
* Moving `test_count_digits` to format-impl-test then count_digits<4>(internal::uintptr_t) shall not be exported
* retaining _CRT_SECURE_NO_WARNINGS always defined should be no harms.
The gcc-7.2.0 compiler (and others) were giving shadowed variable warnings for this include file. A simple renaming of a couple local variables eliminates the warnings.
* Update format.cc
As the explicit instantiation *declaration* of `internal::basic_data<void>` in format.h, this explicit instantiation *definition* should mirror FMT_API also.
* Mirror visibility of explicit instantiation declaration
explicit instantiation declaration of internal::basic_data<void> should mirror visibility of FMT_API
* Eliminate `__declspec(dllexport)` designation on extern template internal::basic_data<> when `extern` affected during exporting phase.
* Add `FMT_EXTERN_TEMPLATE_API` for designate DLL export `extern template`
When exporting DLL, do not designate `__declspec(dllexport)` any template that has any explicit class template declaration a.k.a. `extern template`. Instead, designate `__declspec(dllexport)` at single point where we have explicit class template definition a.k.a. normal instantiation without `extern`
Note: this is a c++11 feature.
* Delete whole `FMT_USE_EXTERN_TEMPLATES` block and its condition
1. Remove whole `FMT_USE_EXTERN_TEMPLATES` block
(trailing `FMT_UDL_TEMPLATE` block)
````
#ifndef FMT_USE_EXTERN_TEMPLATES
# ifndef FMT_HEADER_ONLY
# define FMT_USE_EXTERN_TEMPLATES \
((FMT_CLANG_VERSION >= 209 && __cplusplus >= 201103L) || \
(FMT_GCC_VERSION >= 303 && FMT_HAS_GXX_CXX11))
# else
# define FMT_USE_EXTERN_TEMPLATES 0
# endif
#endif
````
2. Delete `FMT_USE_EXTERN_TEMPLATES` condition, only condition, that trailing basic_data class template definition.
````
#if FMT_USE_EXTERN_TEMPLATES
extern template struct basic_data<void>;
#endif
````
3. Replace `FMT_API` with new `FMT_EXTERN_TEMPLATE_API` added in `core.h` for sake of extern template of `basic_data<void>`
* Add `#define FMT_EXTERN extern` only when not `FMT_HEADER_ONLY`
* Replace `extern` on basic_data<void> with the `FMT_EXTERN` condition in core.h
* replace misspelled if !define() with ifndef
