abs

int i = -1;
assert(i.abs == 1);
static assert(is(typeof(i.abs) == int));

uint u = 1;
assert(u.abs == 1);
static assert(is(typeof(u.abs) == uint));

float f = -1.64;
assert(f.abs == 1.64F);
static assert(is(typeof(f.abs) == float));

double d = -1.64;
assert(d.abs == 1.64);
static assert(is(typeof(d.abs) == double));

real r = -1.64;
assert(r.abs == 1.64L);
static assert(is(typeof(r.abs) == real));