Question

The following code will cause compile errors in g++4.4:

// File test.cpp
namespace A
{
    #include <iostream>
}

int main()
{
    return 0;
}

I have this requirement because some third party library comes without namespace protected, and if I directly include these headers, my namespace is polluted.

As a result, I tried to create namespaces for those libraries, but if the library includes some "std headers" the above approach will fail.

Answer 1

I believe 17.4.2.1 [lib.using.headers] forbids including standard library headers in a namespace :

A translation unit shall include a header only outside of any external declaration or definition, and shall
include the header lexically before the first reference to any of the entities it declares or first defines in that
translation unit.

I don’t think there is anything you can do besides filing a request to the library author.