[Issue 21738] std.format.spec: singleSpec should throw on "%%"

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=21738

--- Comment #1 from Dlang Bot <dlang-bot at dlang.rocks> ---
@wolframw created dlang/phobos pull request #7894 "Issue 21738 -
std.format.spec: singleSpec should throw on "%%"" mentioning this issue:

- Issue 21738 - std.format.spec: singleSpec should throw on "%%"

https://github.com/dlang/phobos/pull/7894

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