How to initialize an unsigned long long type?

Question

I'm trying to initialize an unsigned long long int type. But the compiler is throwing an error

"error: integer constant is too large for "long" type ".

The initialization is shown below :

unsigned long long temp = 1298307964911120440;

Can anybody please let me know what the problem is and suggest a solution for the same.

Solution 1

Try suffixing your literal value with ULL

Solution 2

First, be sure your compiler supports the long long type. Second, add a "ULL" suffix to the number.

Solution 3

Q: How to initialize an unsigned long long type?

A: With an unsigned long long constant!

(Add suffix ULL to the constant.)

Comments

[GManNickG]

Just to clarify, unsigned long long has to be at least 64-bits.

[Michael Aaron Safyan]

@GMan, unsigned long long doesn't have to be anything until C++0x officially becomes ISO C++ 2011. It would be far more portable to use uint64_t from <inttypes.h>, assuming both the header and type exist.

[GManNickG]

@Michael: I thought it was implicit that we were talking about the future, since Jerry says "be sure your compiler supports the long long type". Anyway, I agree if we wanted to force a number to be exactly 64-bit, that would be better, but if we just want a large-number-guaranteed-to-be-at-least-64-bits, unsigned long long would be better.

[Steve Jessop]

@GMan: or uint_least64_t. cstdint is going to be in C++0x too.

[GManNickG]

@Steve: Oh yes, I forgot about those. I change my choice to that instead. :]