size-t

Having just read: Does "std::size_t" make sense in C++? I realize using ::size_t is not standards-compliant (although supported by my compiler) when you #include <cstddef> . I want to comply with the standard, but I do not want to prepend std:: to all of my size_t 's. So, what is the more customary/popular way to handle this: write using std::size_t; ? include <stddef.h> ? just rely on compiler support? something else? Bob Miller You should specify it with the using directive. using std::size_t; Add it either to the global scope of each compilation unit, or to the local scopes if it would

size_t is declared as unsigned int so it can't represent negative value. So there is ssize_t which is the signed type of size_t right? Here's my problem: #include <stdio.h> #include <sys/types.h> int main(){ size_t a = -25; ssize_t b = -30; printf("%zu\n%zu\n", a, b); return 0; } why i got: 18446744073709551591 18446744073709551586 as result? I know that with size_t this could be possible because it is an unsigned type but why i got a wrong result also with ssize_t ?? In the first case you're assigning to an unsigned type - a . In the second case you're using the wrong format specifier. The

I want to allocate a 2.9GB char array with database = (char*) malloc((2900 * 1000000 * sizeof(char))); This gives an integer overflow warning and the malloc returns NULL . The malloc parameter is of type size_t which according to documentation is of type unsigned int . So the max should be UINT_MAX which is at least 2.9GB. However, if I try to allocate more than MAX_INT the malloc fails. Does this mean size_t on my system is of type int? How do I check this? I looked through /usr/include/stdlib.h and ./lib/gcc/x86_64-redhat-linux/4.1.1/include/stddef.h but can't find the definition of size_t .

This question already has answers here : What is size_t in C? (12 answers) Closed 4 years ago . First of all, what do I mean, by 'correct definition`? For example, K&R in "C Programming Language" 2nd ed. , in section 2.2 Data Types and Sizes , make very clear statements about integers: There are short , int and long for integer types. They are needed to repesent values of different boundaries. int is a "naturally" sized number for a specific hardware, so also probably the most fastest. Sizes for integer types short , int and long are purely implementation-dependent. But they have restrictions.

Is there any way to give printf a size_t without either casting it first or generating a compiler warning? (I always compile with -Wall .) printf("%zu", sizeof(whatever)); 来源： https://stackoverflow.com/questions/4150056/printf-for-size-t

The Objective-C Runtime provides the class_addIvar C function : BOOL class_addIvar(Class cls, const char *name, size_t size, uint8_t alignment, const char *types) What do I put for size and alignment ? I'm adding an instance variable of type UITextPosition * , but no UITextPosition object is in scope. For size , can I just do sizeof(self) , where self is a subclass of UITextField ? I.e., can I assume that a UITextPosition object is the same size as a UITextField object? How do I get alignment ? The documentation on this stuff is not very informative, which does reflect that generally you