[question] Should the STB recipe implementations be static libraries?

[Sebanisu]

The stb recipe is added via target_include_libraries(... stb::stb ...)

I was thinking maybe we should have static libraries added for the implimentations.

#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "stb_image_write.h"

#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"

#define STB_DEFINE
#include "stb.h"

Where the library defined just includes the header after the #define or use target_compile_definitions. Then we can just add that to our include target_include_libraries(... stb::stb_main stb::image stb::image_write ...) and these libraries could have public includes of stb::stb

example cmake:

find_package(stb REQUIRED)
add_library(stbi_wrapper STATIC
        stbi.cpp)
target_link_libraries(stbi_wrapper
        PUBLIC stb::stb
        )
target_compile_definitions(stbi_wrapper
        PRIVATE STB_IMAGE_IMPLEMENTATION)

example cpp file:

#include <stb_image.h>

I used this in my project. I was getting a compiler error after enabling precompiled headers. So I used this small static library to offload the building of the implementation.

[SpaceIm]

C header only libraries with implementation macro are evil.

Regarding your suggestion:

Pros:

• reduce compilation time for consumers
• avoid ODR violation

Cons:

• add as many recipe options as implementation macros
• may be misleading for consumers since they expect a C header-only library
• you need to ensure that implementation macro are completely neutralized in installed public headers, because consumers may not be aware of these tricks done in conan recipe and they may define again implementation macro, leading to ODR violation.

Actually, I've implemented this logic in cgltf recipe, but I don't know whether it was a good idea.

[Sebanisu]

I think the default could be the current behavior so not to break anyone's code. I think having the recipe options could be nice to have.