Bug 18822 – [REG 2.080.0] Compiling byGrapheme Fails

CODE: void main() { import std.uni; string a = "test"; auto b = a.byGrapheme; } $ dmd --version DMD64 D Compiler v2.080.0 $ dmd -unittest -main -run source/yarn.d /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(7010): Error: forward reference to inferred return type of function call hangLV() /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(7040): Error: forward reference to inferred return type of function call hangLV() /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(7110): Error: template instance `std.uni.genericDecodeGrapheme!false.genericDecodeGrapheme!(const(char)[])` error instantiating /usr/local/opt/dmd/include/dlang/dmd/std/format.d(3206): instantiated from here: graphemeStride!char /usr/local/opt/dmd/include/dlang/dmd/std/format.d(2890): instantiated from here: formatRange!(Appender!string, string, char) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(1845): instantiated from here: formatValueImpl!(Appender!string, string, char) /usr/local/opt/dmd/include/dlang/dmd/std/array.d(3268): ... (7 instantiations, -v to show) ... /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(10432): instantiated from here: CodepointTrie!(bool, 8, 5, 8) /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(10502): instantiated from here: asTrie!(bool, 8, 5, 8) /usr/local/opt/dmd/include/dlang/dmd/std/conv.d(1018): Error: template instance `std.conv.toStr!(string, char)` error instantiating /usr/local/opt/dmd/include/dlang/dmd/std/conv.d(222): instantiated from here: toImpl!(string, char) /usr/local/opt/dmd/include/dlang/dmd/std/conv.d(4255): instantiated from here: to!char /usr/local/opt/dmd/include/dlang/dmd/std/conv.d(4194): instantiated from here: textImpl!(string, string, char) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(486): ... (13 instantiations, -v to show) ... /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(10432): instantiated from here: CodepointTrie!(bool, 8, 5, 8) /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(10502): instantiated from here: asTrie!(bool, 8, 5, 8) /usr/local/opt/dmd/include/dlang/dmd/std/conv.d(4194): Error: template instance `std.conv.textImpl!(string, string, string, string)` error instantiating /usr/local/opt/dmd/include/dlang/dmd/std/format.d(4509): instantiated from here: text!(string, string, string) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(4484): instantiated from here: getNth!("integer width", isIntegral, int, uint) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(492): instantiated from here: getNthInt!("integer width", uint) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(3400): ... (12 instantiations, -v to show) ... /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(10432): instantiated from here: CodepointTrie!(bool, 8, 5, 8) /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(10502): instantiated from here: asTrie!(bool, 8, 5, 8) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(4484): Error: template instance `std.format.getNth!("integer precision", isIntegral, int, uint)` error instantiating /usr/local/opt/dmd/include/dlang/dmd/std/format.d(518): instantiated from here: getNthInt!("integer precision", uint) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(3400): instantiated from here: formattedWrite!(Appender!string, char, uint) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(3496): instantiated from here: formatChar!(Appender!string) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(3339): ... (10 instantiations, -v to show) ... /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(10432): instantiated from here: CodepointTrie!(bool, 8, 5, 8) /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(10502): instantiated from here: asTrie!(bool, 8, 5, 8) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(4484): Error: template instance `std.format.getNth!("separator digit width", isIntegral, int, uint)` error instantiating /usr/local/opt/dmd/include/dlang/dmd/std/format.d(538): instantiated from here: getNthInt!("separator digit width", uint) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(3400): instantiated from here: formattedWrite!(Appender!string, char, uint) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(3496): instantiated from here: formatChar!(Appender!string) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(3339): ... (10 instantiations, -v to show) ... /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(10432): instantiated from here: CodepointTrie!(bool, 8, 5, 8) /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(10502): instantiated from here: asTrie!(bool, 8, 5, 8) /usr/local/opt/dmd/include/dlang/dmd/std/conv.d(4194): Error: template instance `std.conv.textImpl!(string, string, string, string, string, uint)` error instantiating /usr/local/opt/dmd/include/dlang/dmd/std/format.d(4503): instantiated from here: text!(string, string, string, string, uint) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(546): instantiated from here: getNth!("separator character", isSomeChar, dchar, uint) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(3400): instantiated from here: formattedWrite!(Appender!string, char, uint) /usr/local/opt/dmd/include/dlang/dmd/std/format.d(3496): ... (11 instantiations, -v to show) ... /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(10432): instantiated from here: CodepointTrie!(bool, 8, 5, 8) /usr/local/opt/dmd/include/dlang/dmd/std/uni.d(10502): instantiated from here: asTrie!(bool, 8, 5, 8) /usr/local/opt/dmd/include/dlang/dmd/std/conv.d(4194): Error: template instance `std.conv.textImpl!(string, string, ubyte, char, char, string, ulong)` error instantiating

Introduced in https://github.com/dlang/phobos/pull/6235 So, what's happening is that the toString of Appender now uses formatValue, which calls formatRange, which calls graphemeStride. Grapheme uses TrieBuilder, which uses std.conv.text for an error message which uses Appender, and you can see the problem.

Commits pushed to master at https://github.com/dlang/phobos https://github.com/dlang/phobos/commit/707c50b90c0799aa642bf530c8b35fe237ab5052 Fix Issue 18822 - Compiling byGrapheme Fails https://github.com/dlang/phobos/commit/0b15d73d6b60c71c1f98f38b16666db9340564b5 Merge pull request #6493 from JackStouffer/issue18822 Fix Issue 18822 - Compiling byGrapheme Fails