About the 'unsigned long long' type
I am reading stdio.h to learn more functions and stardard declarations.
When I see atoll function, I find its return type is odd: long long int
And there are more functions return odd types, such as unsigned long int, unsigned long long int
What do they mean? Take 'long long' type for example, if long is 32 bits, does long long has 64-bit precision?
And I try to find some type like 'double double' but find nothing. Will it work if I use double double?