If a C++ program includes a standard header (I use <string.h> in my example), a typedef

    typedef unsigned int uint;

becomes visible. The identifier does not appear in the 2011 ISO C++ standard.

The problem occurs with "g++ -std=c++11 -pedantic". It does not occur with "g++ -std=c++03 -pedantic".

To demonstrate:

    $ cat uint_bug.cpp
    #include <string>
    int uint;
    int main() { }
    $ g++ --version 
    g++ (Ubuntu/Linaro 4.7.2-2ubuntu1) 4.7.2
    Copyright (C) 2012 Free Software Foundation, Inc.
    This is free software; see the source for copying conditions.  There is NO
    warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

    $ g++ -std=c++03 -pedantic -c uint_bug.cpp
    $ g++ -std=c++11 -pedantic -c uint_bug.cpp
    uint_bug.cpp:2:5: error: ‘int uint’ redeclared as different kind of symbol
    In file included from /usr/include/stdlib.h:320:0,
                     from /usr/include/c++/4.7/cstdlib:66,
                     from /usr/include/c++/4.7/ext/string_conversions.h:37,
                     from /usr/include/c++/4.7/bits/basic_string.h:2814,
                     from /usr/include/c++/4.7/string:54,
                     from uint_bug.cpp:1:
    /usr/include/x86_64-linux-gnu/sys/types.h:153:22: error: previous declaration of ‘typedef unsigned int uint’
    $

Running "g++ -std=c++11 -E uint_bug.cpp" shows that the declaration "typedef int uint;", along with similar declarations for "ushort" and "ulong", appears in /usr/include/x86_64-linux-gnu/sys/types.h. Apparently the macro __USE_MISC is defined. (The same macro appears to be defined with "-std=c++03", but the problem doesn't occur with that option; I haven't figured out why.)

I'm not sure whether the bug is in the compiler or in the libc headers.

(The same problem occurs with clang++ version 3.4.)