Bug 20924 – std.numeric.gcd cannot be used with const BigInt

Code: ---------- import std.bigint; import std.numeric; import std.stdio; void main() { const a = BigInt("123143238472389492934020"); const b = BigInt("902380489324729338420924"); writeln(gcd(a, b)); } ---------- Compiler output: ---------- /usr/src/d/phobos/std/numeric.d(3044): Error: template std.bigint.BigInt.opAssign cannot deduce function from argument types !()(BigInt) const, candidates are: /usr/src/d/phobos/std/bigint.d(178): opAssign(T)(T x) /usr/src/d/phobos/std/bigint.d(194): opAssign(T : BigInt)(T x) /usr/src/d/phobos/std/numeric.d(3045): Error: template std.bigint.BigInt.opAssign cannot deduce function from argument types !()(const(BigInt)) const, candidates are: /usr/src/d/phobos/std/bigint.d(178): opAssign(T)(T x) /usr/src/d/phobos/std/bigint.d(194): opAssign(T : BigInt)(T x) test.d(7): Error: template instance std.numeric.gcd!(const(BigInt)) error instantiating ---------- There's no reason why const BigInt shouldn't work with gcd, since gcd doesn't (shouldn't!) modify its arguments, and the following does work: ---------- import std.bigint; //import std.numeric; // NG import std.stdio; // Copy-n-pasted code from std.numeric.gcd BigInt gcd(in BigInt a, in BigInt b) { BigInt ua = a; BigInt ub = b; while (ub) { auto t = ub; ub = ua % ub; ua = t; } return ua; } void main() { const a = BigInt("123143238472389492934020"); const b = BigInt("902380489324729338420924"); writeln(gcd(a, b)); } ---------- Program output: 12

@Biotronic created dlang/phobos pull request #7531 "Fix issue 20924 - std.numeric.gcd cannot be used with const BigInt" fixing this issue: - Fix issue 20924 https://github.com/dlang/phobos/pull/7531

dlang/phobos pull request #7531 "Fix issue 20924 - std.numeric.gcd cannot be used with const BigInt" was merged into master: - a10a3a43efe2eb24e49fccb1b06b56f87e234901 by Simen Kjærås: Fix issue 20924 https://github.com/dlang/phobos/pull/7531