The current cmake configuration for ztd.idk is not header-only, it produces a library from the files in the source directory.

This is a problem, because the API linkage flag that api.h expects to see (ZTD_DLL) isn't set by the build system, so the library is built without exporting any symbols. This makes the library unlinkable on Windows.

This is all fixable, but I need to know the intent. The docs refer to idk as header only and it appears to work entirely in header-only mode. So should we just not compile these files? Should we create two targets, one for header only and one that compiles and links the library correctly?

Once I know what the intent is I can handle fixing up the cmake stuff.

@ThePhD ,how are you? I want to add some projects of you to vcpkg, but fail to compile idk on android.
install-arm-neon-android-dbg-out.log
microsoft/vcpkg#34735
Error message:
/mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/include/ztd/idk/span.hpp:130:18: error: no member named 'operator==' in namespace 'nonstd'
using ::nonstd::operator==;
~~~~~~~~~~^
/mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/include/ztd/idk/span.hpp:131:18: error: no member named 'operator!=' in namespace 'nonstd'
using ::nonstd::operator!=;
~~~~~~~~~~^
/mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/include/ztd/idk/span.hpp:132:18: error: no member named 'operator<' in namespace 'nonstd'
using ::nonstd::operator<;
~~~~~~~~~~^
/mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/include/ztd/idk/span.hpp:133:18: error: no member named 'operator<=' in namespace 'nonstd'
using ::nonstd::operator<=;
~~~~~~~~~~^
/mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/include/ztd/idk/span.hpp:134:18: error: no member named 'operator>' in namespace 'nonstd'
using ::nonstd::operator>;
~~~~~~~~~~^
/mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/include/ztd/idk/span.hpp:135:18: error: no member named 'operator>=' in namespace 'nonstd'
using ::nonstd::operator>=;
~~~~~~~~~~^
In file included from /mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/source/ztd/idk/encoding_detection.c.cpp:35:
In file included from /mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/include/ztd/idk/encoding_name.hpp:39:
/mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/include/ztd/idk/char_traits.hpp:58:22: error: no type named 'mbstate_t' in namespace 'std'; did you mean simply 'mbstate_t'?
using state_type = ::std::mbstate_t;
^~~~~~~~~~~~~~~~
mbstate_t
/android-ndk-r25c/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/include/bits/mbstate_t.h:47:3: note: 'mbstate_t' declared here
} mbstate_t;
^
In file included from /mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/source/ztd/idk/encoding_detection.c.cpp:37:
/mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/include/ztd/idk/detail/posix.hpp:70:25: error: use of undeclared identifier 'nl_langinfo'
const char* __name = nl_langinfo(LC_CTYPE);
^
/mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/source/ztd/idk/encoding_detection.c.cpp:65:29: error: use of undeclared identifier 'nl_langinfo'
const char* __ctype_name = nl_langinfo(CODESET);
^
/mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/source/ztd/idk/encoding_detection.c.cpp:108:29: error: use of undeclared identifier 'nl_langinfo'
const char* __ctype_name = nl_langinfo(CODESET);
^
/mnt/vcpkg-ci/buildtrees/ztd-idk/src/f54d488079-38e2ce903b.clean/source/ztd/idk/encoding_detection.c.cpp:228:29: error: use of undeclared identifier 'nl_langinfo'
const char* __ctype_name = nl_langinfo(CODESET);
^
11 errors generated.

<functional> is a huge header, containing (but not limited to) hash, reference_wrapper, function, invoke and much more. Most of the time all these classes are not needed at the same place at the same time, so a #include <functional> may be something expensive, especially on headers (for example reference_wrapper.hpp). Thus I propose to add a new header on ztd/idk/detail named invoke.hpp which provides an implementation of std::invoke/std::invoke_result/std::is_invocable named __ztd_detail::{__invoke, __invoke_result, __is_invocable} and replace the use of the equivalent std:: classes over the library. A reference implementation of std::invoke can be found here.

Used here:

No idea if Windows UWP is a platform ya'll care about, but right now that's the only target unavailable for vcpkg because of the issue title.

I got an error when compile with ztd.text (msvc 19.39 with c++latest) at this line
https://github.com/soasis/text/blob/fc30abbc3056a0ea69f2c6ef25221c3244bf31cf/include/ztd/text/detail/span_reconstruct.hpp#L90

Look like ::ztd::ranges::range_element_type_t is undefined when ZTD_IS_ON(ZTD_STD_LIBRARY_RANGES) at line 882 in adl.hpp is true

I copy line 916 to 891 and it compiles.

Build failure from a ztd-text include:

In file included from D:/a/vea/vea/vcpkg_installed/x64-windows/include\ztd/text.hpp:56:
D:/a/vea/vea/vcpkg_installed/x64-windows/include\ztd/text/encode_view.hpp:246:24: error: no variable template matches partial specialization
        inline constexpr bool enable_borrowed_range<::ztd::text::encode_view<_Encoding, _Range, _ErrorHandler,
                              ^
D:/a/vea/vea/vcpkg_installed/x64-windows/include\ztd/text/encode_view.hpp:247:14: error: no template named 'enable_borrowed_range' in namespace 'ztd::ranges'; did you mean 'std::ranges::enable_borrowed_range'?
                _State>> = ::ztd::ranges::enable_borrowed_range<_Range>;
                           ^~~~~~~~~~~~~~~
C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.31.31103\include\xutility:1973:27: note: 'std::ranges::enable_borrowed_range' declared here
    inline constexpr bool enable_borrowed_range = false;
                          ^