Compiler gets confused with ambiguity when `int` matches both `real` and `float`.

[IM via Digitalmars-d-learn]

The following expression:

import std.math : sqrt;
sqrt(400);
produces the following compiler error:

std.math.sqrt called with argument types (int) matches both:
/usr/include/dmd/phobos/std/math.d(1592,7):     
std.math.sqrt(float x)
and:
/usr/include/dmd/phobos/std/math.d(1598,6):     
std.math.sqrt(real x)

Shouldn't it just pick one according to some defined rules?