Does returning a standard container incur a copy of the contents of the container?

Question

If I have a function that returns an STL container am I incurring a copy of the entire contents of the standard container?

e.g. Is this:

void Foo( std::vector< std::string >* string_list );

better than this:

std::vector< std::string > Foo();

Does it matter what's in the container? For instance would returning a container like this:

struct buzz {
    int a;
    char b;
    float c;
}

std::map< int, buzz > Foo();

be a more costly operation than this:

std::map< int, int > Foo();

Thanks, PaulH

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Edit: This is with C++03. A C++0x solution is, unfortunately, not acceptable.

Edit2: I am using the Microsoft Visual Studio 2008 compiler.

Answer 1

C++03 will probably do (named) return value optimization (google RVO and NRVO).

If that optimization is not applicable, C++0x will do move semantics.