std::string in a .c file

Question

I've seen std::string used in a .c file. std is a c++ namespace and namespaces were introduced in c++. Why is that so? Shouldn't it throw an error?

This is your answer. Flagged as duplicate. http://stackoverflow.com/questions/1545080/correct-c-code-file-extension-cc-vs-cpp — ApplePie, Oct 22 '12 at 23:22
File extensions don't matter, I can write code in a *.mp3 file, and my compiler will happily compile it as C++ if I ask it to. — Praetorian, Oct 22 '12 at 23:22
@Praetorian: [But maybe not a .png file.](http://stackoverflow.com/questions/5508110/why-is-this-program-erroneously-rejected-by-three-c-compilers) — James McNellis, Oct 22 '12 at 23:28
@JamesMcNellis, I think there's a video somewhere of someone imaging a BMP or something and changing the extension to a working C++ program. — chris, Oct 22 '12 at 23:33

score 9 · Accepted Answer · answered Oct 22 '12 at 23:23

Yes, it will cause numerous compiler errors if it's compiled as C code. If it's being compiled as C++ instead, then it will compile fine. For example, GCC has the -x option to select the language to compile as, so you can compile a .c as C++ if you want with -x c++. Likewise, the Microsoft Visual C++ compiler has the options /Tc and /Tp to select a source language of C and C++ respectively.

I suggest you fix your build system so that it doesn't pass the -x c++ or /Tp flag to files not ending with typical C++ source file extensions (.cc, .cpp, .cxx, c++, and .C, though the last three are quite rare).

score 1 · Answer 2 · answered Oct 22 '12 at 23:23

1

The extension of a file is only there to help you as the reader. The compiler does not care as long as you use a c++ compiler.

answered Oct 22 '12 at 23:23

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std::string in a .c file

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