MISRA.NS.GLOBAL.USING

The global namespace shall not contain using directives and declarations.

MISRA-C++ Rule 7-3-1 (required): The global namespace shall only contain main, namespace declarations and extern "C" declarations.

Rationale

Declaring names into appropriate namespaces reduces the names found during lookup, helping to ensure that the names found meet developer expectations.

Exception

The types defined for compliance with Rule 3—9—2 may also be in the global namespace.

Example

namespace std        // Compliant
{
    namespace Inner
    {
        int x;
    }
}

using namespace std; // Non-compliant
using std::Inner::x; // Non-compliant

namespace Outer
{
    using  Inner::x; // Compliant
}

int main ( )         // Compliant
{
    return 0;
}