size-t

I want to print out a variable of type size_t in C but it appears that size_t is aliased to different variable types on different architectures. For example, on one machine (64-bit) the following code does not throw any warnings: size_t size = 1; printf("the size is %ld", size); but on my other machine (32-bit) the above code produces the following warning message: warning: format '%ld' expects type 'long int *', but argument 3 has type 'size_t *' I suspect this is due to the difference in pointer size, so that on my 64-bit machine size_t is aliased to a long int ( "%ld" ), whereas on my 32

I'm just wondering should I use std::size_t for loops and stuff instead of int ? For instance: #include <cstdint> int main() { for (std::size_t i = 0; i < 10; ++i) { // std::size_t OK here? Or should I use, say, unsigned int instead? } } In general, what is the best practice regarding when to use std::size_t ? A good rule of thumb is for anything that you need to compare in the loop condition against something that is naturally a std::size_t itself. std::size_t is the type of any sizeof expression and as is guaranteed to be able to express the maximum size of any object (including any array)

Bjarne Stroustrup wrote in The C++ Programming Language: The unsigned integer types are ideal for uses that treat storage as a bit array. Using an unsigned instead of an int to gain one more bit to represent positive integers is almost never a good idea. Attempts to ensure that some values are positive by declaring variables unsigned will typically be defeated by the implicit conversion rules. size_t seems to be unsigned "to gain one more bit to represent positive integers". So was this a mistake (or trade-off), and if so, should we minimize use of it in our own code? Another relevant article