size_tis a return type of operator sizeofand is used to describe memory sizes. In the case, memsetit indicates the number of bytes (n) in the memory block, which should be set to the set value (c).
The size in bits size_tdepends on the address space of the target platform. It does not always correlate with register size. For example, in a segmented memory architecture, there sizeof (size_t)may be less than sizeof (void *). As a rule, there size_twill be 4 bytes on a 32-bit machine, 8 bytes on a 64-bit machine, etc.
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