Bug 7774 – Floating point mod using %= does not properly update field while inside member function

Try next code: import std.stdio; template TX(T) { struct A { T x; T y; public void opOpAssign(string op)(double d) { debug writeln(op); if (op == "+")// += { x += cast(T)d; y += cast(T)d; } else if (op == "-") // -= { x -= cast(T)d; y -= cast(T)d; } else if (op == "*") // *= { x *= cast(T)d; y *= cast(T)d; } else if (op == "/") // /= { x /= cast(T)d; y /= cast(T)d; } else if (op == "%") // %= { x %= cast(T)d; y %= cast(T)d; } } } } void main(string[] args) { TX!(double).A a; a.x =10; a.y = 10; a%=8.0; writeln(a.x, " ", a.y); } You'll see that the a.x won't change. It must be 2 after %= operation. Thank you.

I'm using your exact code, it works fine here on dmd2.059head win7 and prints 2 2 Your version of dmd, system spec? PS: I totally expected thouse ifs to be static ifs.

If confirmed this bug report needs a better name :-) (In reply to comment #1) > PS: I totally expected thouse ifs to be static ifs. Those variables are known at compile-time, so a good compiler is supposed to remove the useless if branches (quite probably dmd does it).

You have found a bug in DMD 2.058, not in D2. Smaller test case: struct A{ double x; void f(double d){x%=cast(double)d;} } void main(){ auto a=A(10); a.f(8); assert(a.x!=10.0); } Works with DMD 2.059head, fails with DMD 2.058.

(In reply to comment #3) > You have found a bug in DMD 2.058, not in D2. > > > Smaller test case: > struct A{ > double x; > void f(double d){x%=cast(double)d;} > } > void main(){ > auto a=A(10); > a.f(8); > assert(a.x!=10.0); > } > > Works with DMD 2.059head, fails with DMD 2.058. How can I get a DMD 2.059 linux version or DMD 2.0?

(In reply to comment #4) > > How can I get a DMD 2.059 linux version or DMD 2.0? It hasn't been released yet, but you can build it from source: https://github.com/D-Programming-Language/dmd

The proper designation for this bug should be either "Fixed" or "Duplicate". I don't know which, because I don't know enough about the compiler to find out which code changed. Correcting description. Please try and create a better description next time, thanks.