The size_t type is the unsigned integer type of the result of the sizeof operator. Variables of type size_t are guaranteed to be of sufficient precision to represent the size of an object. The limit of size_t is specified by the SIZE_MAX macro.
Wiki Markup size_t}} generally covers the entire address space. ISO/IEC TR 24731-1-2007 introduces a new type {{rsize_t}}, defined to be {{size_t}} but explicitly used to hold the size of a single object \[[ISO/IEC TR 24731-1:2007|AA. C References#ISO/IEC TR 24731-1-2007]\]. In code that documents this purpose by using the type {{rsize_t}}, the size of an object can be checked to verify that it is no larger than {{RSIZE_MAX}}, the maximum size of a normal single object, which provides additional input validation for library functions. See [STR07-C. Use TR 24731 for remediation of existing string manipulation code] for additional discussion of TR 24731-1.
Any variable that is used to represent the size of an object, including integer values used as sizes, indices, loop counters, and lengths, should be declared as rsize_t if available, or otherwise as size_t.
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