Question

unsigned long long value = 0;

bool result = value >= std::numeric_limits<signed int>::min();

This should give true but gives false? Why and how can I fix it?

Answer 1

The int converts to an unsigned int for comparison. You could cast your unsigned long long to a long long.

5/9:

Many binary operators that expect
operands of arithmetic or enumeration
type cause conversions and yield
result types in a similar way. The
purpose is to yield a common type,
which is also the type of the result.
This pattern is called the usual
arithmetic conversions, which are
defined as follows:

…

Then, if
either operand is unsigned long the
other shall be converted to unsigned
long.

…

Otherwise, if either operand is
unsigned, the other shall be converted
to unsigned.

unsigned long long and long long are not standard types in c++03, but it’s quite likely that the compiler will treat these types using the mechanisms defined above. The mentioned conversion rules would then cover this particular conversion.