Bug 7996 – Refuse std.math.isnan() on not floating point values?

std.math.sqrt() refuses an argument of type long (despite this is handy): import std.math; void main() { long x; sqrt(x); } With (dmd 2.060alpha): test.d(4): Error: function std.math.sqrt called with argument types: ((long)) matches both: std.math.sqrt(float x) and: std.math.sqrt(real x) While this compiles with no errors: import std.math; void main() { long x; assert(!isnan(x)); } Maybe isnan() has to statically refuse arguments that aren't built-in floating point (maybe with a std.traits.isFloatingPoint template constraint), this avoids some bugs (I have had a bug caused by this).

(In reply to bearophile_hugs from comment #0) > std.math.sqrt() refuses an argument of type long (despite this is handy): > > import std.math; > void main() { > long x; > sqrt(x); > } > > > > With (dmd 2.060alpha): > > test.d(4): Error: function std.math.sqrt called with argument types: > ((long)) > matches both: > std.math.sqrt(float x) > and: > std.math.sqrt(real x) > > > > While this compiles with no errors: > > import std.math; > void main() { > long x; > assert(!isnan(x)); > } > > > Maybe isnan() has to statically refuse arguments that aren't built-in > floating point (maybe with a std.traits.isFloatingPoint template > constraint), this avoids some bugs (I have had a bug caused by this). Actually, the function isnan is deprecated. Instead, the function isNaN has the constraint isFloatingPoint [1]. Maybe this should be closed? [1] https://dlang.org/phobos/std_math#.isNaN