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c++macrosc-preprocessorvariadic

Variadic Macro with 3 terms

I am trying to understand a C++ code that reads a dll explicitly. Does any one know how the line #define LFE_API(name) LFE_##name name below actually works? I understand #define LFE_API(name) LFE_##name but get confused about the last "name".

    struct Interface
{
    #   ifdef LFE_API
    #       error You can't define LFE_API before. 
    #   else
    #       define LFE_API(name) LFE_##name name
                LFE_API(Init);
                LFE_API(Close);
                LFE_API(GetProperty);
    #       undef LFE_API
    #   endif
};
Solution

  • Since the first part of the macro (LFE_##name) just concatenates both parts, a call to LFE_API is creating a variable named name with the type LFE##name, such as:

    LFE_API(Init) expands to LFE_Init Init;