Why does MSVC pick a long long as the type for -2147483648?
Contrary to popular belief, -2147483648 is not a literal: C++ does not support negative literal values.
It is, in fact, a compile-time evaluable constant expression consisting of a unary negation of the literal 2147483648.
On MSVC x64, which has 32 bit ints and longs, 2147483648 is too big for either of those so it fails over to the long long type that you observe.