With 2.049, this code:
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module scratch;
import std.math;
void foo() {
float a = 1, b = 1.00000000001;
auto same = feqrel( a, b ) > 15;
}
==========
Emits this diagnostic:
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$ dmd scratch.d
d:\Devel\D\dmd2\windows\bin\..\..\src\phobos\std\math.d(3286): Error: function std.math.feqrel!(float).feqrel has no return statement, but is expected to return a value of type int
d:\Devel\D\dmd2\windows\bin\..\..\src\phobos\std\math.d(8): Error: template instance std.math.feqrel!(float) error instantiating
==========