When developing a C++ library, how you export your public headers directly impacts how easily and safely others can use your code. Adopting best practices for exporting headers avoids common pitfalls, such as symbol conflicts, multiple inclusion errors, and platform-specific linking problems.

First, always use include guards in your public headers. Include guards prevent the same header from being included more than once in a single translation unit, which can otherwise cause redefinition errors. The typical pattern uses #ifndef, #define, and #endif, with a unique macro name that reflects the header's path.

Second, use an export macro to control symbol visibility when your library is built as a shared library. This macro should expand to the correct compiler-specific attribute for exporting or importing symbols (__declspec(dllexport) or __declspec(dllimport) on Windows, and __attribute__((visibility("default"))) on GCC/Clang). Place this macro before the declarations of classes or functions that you want to make available to library users. By defining the macro differently when building versus consuming the library, you ensure correct symbol export and import semantics across platforms.

Finally, structure your public headers in a dedicated directory, such as include/yourlib/. This makes it clear to users which headers are part of your library's public API, and it helps avoid accidental exposure of internal implementation details.

Combining these practices—include guards, export macros, and a clear directory layout—ensures your library's headers are robust, portable, and easy to consume.