[CalChris]

This is similar to the C preprocessor trick STRINGIZE:

  #define STRINGIZE_DETAIL(x) #x
  #define STRINGIZE(x)        STRINGIZE_DETAIL(x)

[gpderetta]

It probably uses stringification under the hood, but then relies on constexpr to "canonicalize" the name (removing everything before the dot, template parameters etc).

[Someone]

From cursory reading, it seems it doesn’t, at all. It uses compiler-specific predefined values __PRETTY_FUNCTION__ (gcc, clang) or __FUNCSIG__ (MS Visual C++), and doesn’t work on other compilers.

It also has to do work to extract the function name from the char arrays/C strings that those macros expand to.

Reading answers to https://stackoverflow.com/questions/4384765/whats-the-differ..., it seems it would have been easier to use the __FUNCTION__ in gcc, but I’m not familiar with that (or the other predefined values) at all, so who knows?

[anon4242]

Actually, __FUNCTION__ won't work as it only expands to the name of the function, not any templates or arguments.

It's actually a pretty clever way to automagically deduce not only names of variables but also of enums :). Too bad it's most likely not maintainable in the long run as compilers probably change what their __PRETTY_FUNCTION__ (or equivalent) macros expand to in new versions.

[neargye]

I usually check the newest versions of compilers, and if the behavior changes, then I update the code

[asveikau]

Last I knew __FUNCTION__ in GCC doesn't even do name de-mangling. You'd get the raw C symbol name with no C++ types.

[neargye]

https://stackoverflow.com/a/31163837/9514814

[asveikau]

Gcc 7. I could be wrong but I seem to recall a long time ago, when I was learning this stuff in the 90s, __FUNCTION__ wouldn't even demangle.

[neargye]

yeap, I use __PRETTY_FUNCTION__.

[neargye]

You are absolutely right :)

[asveikau]

That was what I was thinking, then I saw that this will stringify enum values, eg. nameof(c) returns "RED", which the preprocessor #x will not do.

[neargye]

To be sure: nameof(c) returns "c" (nameof return name of variable) nameof_enum(c) returns "RED" (nameof_enum return enum name of enum variable)

[CalChris]

I only use STRINGIZE for error messages. I learned about it from reading the source for assert macros.