__promise represents a promise you make to the compiler that a given expression always has a nonzero value. This enables the compiler to perform more aggressive optimization when vectorizing code.
is an expression
that evaluates to nonzero.
#include <assert.h> to use
If assertions are enabled (by not defining
NDEBUG) and the macro
__DO_NOT_LINK_PROMISE_WITH_ASSERT is not defined, then the promise is checked at runtime by evaluating
as part of