Bug 4491 – Assigning large const value to ulong type results in "signed integer overflow"

The following code: import std.stdio; void main() { ulong t;// = 18446744073709551615; printf("%llu\n", t.max); } Outputs: 18446744073709551615 However, I get a "signed integer overflow" when I try to assign the value directly. Code: import std.stdio; void main() { ulong t = 18446744073709551615; printf("%llu\n", t); } Outputs: bug.d(4): signed integer overflow Using 'cast(ulong)18446744073709551615' doesn't help either, so I presume this happens before D knows what datatype the large integer will be assigned to. IMO, assignments of constant values within the range of foo.min to foo.max should be allowed for all types.

You need to add an 'L' suffix when it's larger than int.max, and a 'U' suffix when it's unsigned. import std.stdio; void main() { ulong t = 18446744073709551615UL; printf("%llu\n", t); } The error message should make this clearer. Marking as a 'diagnostic' bug.

What's bad in the compiler/language accepting a line like: ulong t = 18446744073709551615;

(In reply to comment #1) > You need to add an 'L' suffix when it's larger than int.max, and a 'U' suffix > when it's unsigned. > > import std.stdio; > void main() > { > ulong t = 18446744073709551615UL; > printf("%llu\n", t); > } > > The error message should make this clearer. Marking as a 'diagnostic' bug. I suppose that makes sense once you know. Though it seems that it should more like syntactical sugar to me, rather than a mandatory marking. For example, "1e6" gets translated to 1_000_000.