Where do I find the definition of size_t?

Question

I see variables defined with this type but I don\'t know where it comes from, nor what is its purpose. Why not use int or unsigned int? (What about other \"similar\" types?

Answer 1

In minimalistic programs where a size_t definition was not loaded "by chance" in some include but I still need it in some context (for example to access std::vector), then I use that context to extract the correct type. For example typedef std::vector::size_type size_t.

(Surround with namespace {...} if necessary to make the scope limited.)