Unsuffixed Decimal Literal Values

Examples of C99 Unsuffixed Constants shows an example of specifying decimal literal values without a suffix to specify the literal's type.

Listing 1. Examples of C99 Unsuffixed Constants

#pragma c99 on  // Note: ULONG_MAX == 4294967295
sizeof(4294967295)  == sizeof(long long)
sizeof(4294967295u) == sizeof(unsigned long)

#pragma c99 off

sizeof(4294967295)  == sizeof(unsigned long)

sizeof(4294967295u) == sizeof(unsigned long)