xcode - C++ std::printf("%u", 5) adds a number after the expected output -

the output of following code 51 instead of expected 5. use xcode 6.4 llvm compiler on mac os yosemite 10.10.4.

#include <iostream>  int main(int argc, const char * argv[]) {   std::cout << std::printf("%u", 5) << std::endl;    return 0; } 

if have tried supply int, unsigned long , uint32_t, , have swapped %u %d , %lu, same result: strange number being after intended printf output. swapping 5 number results in unexpected number being added output. in fresh project no other code added. overlooking?

printf returns int. in case returning 1 number of characters written (5).

cout printing 1, after printf prints 5 because you're chaining them together.

to 5, say:

std::printf("%u\n", 5)