size_t, size_type, unsigned

[asdf]

Who can tell the difference in detail?

 

[Ian Collins]

Who can tell the difference in detail?

Your environment's headers?

 

[Bo Persson]

Who can tell the difference in detail?

size_t is the type of the value returned by sizeof(). It is also a
typedef in some standard headers.

size_type is another typedef used for example in the standard
containers, like std::vector and std::string.

unsigned is a standard type that is built into the compiler. As such,
it is available immediately, without any typedefs.


On some systems, size_t, size_type, and unsigned could all be the same
type. On other systems they might be different. By always using the
proper type, your code has a bigger chance of being portable from one
system to another.



Bo Persson