Point of size_t [duplicate]

This question already has answers here: Closed 12 years ago.

Possible Duplicate:

unsigned int vs. size_t

When I need to store the size of something (usually stuff allocated with 开发者_高级运维new), I always store it in an unsigned int. Browsing through some code, however, I saw size_t used. According to this, it's hardly used for a lot.

• What is the point of size_t in C++?
• Why don't those few functions that use it just use an unsigned int instead?
• How should it be used in new code?

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You could have an array, the size and indexing of which can exceed the range of an int, as an int is only guaranteed 16bits. The practicality of using size_t is rather low right now but may become more important in the future. On MSVC compiling for 64bit, for example, I could have a class, an instance of which is larger than 4GB. Of course, I expect that in practicality, the CRT won't deal with sizes that large, but the Standard is unconcerned with that.