Support constexpr in min and max
#251
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These have been `constexpr` compatible since C++14. Mechanically, the way I did this was: 1. Find an overload that was not `constexpr`. 2. Make a test that requires it to be `constexpr` to pass (either tweaking an existing test, or making a new one). 3. Make sure the test fails. 4. Change the function until the test passes. The biggest challenge was that our default compiler wouldn't accept our lambda in a `constexpr` context. That feels like a bug, but in any case, we were able to work around it by making a manual function object with an explicitly `constexpr` call operator. Fixes #244.
chiphogg
added
the
release notes: ✨ lib (enhancement)
geoffviola
approved these changes
Jun 24, 2024
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The changes make sense. It looks like lambdas in a constexpr context have been added in C++17: https://stackoverflow.com/a/32697323
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Well... that would sure explain why it didn't work before! TIL. |
hoffbrinkle
reviewed
Jun 24, 2024
| @@ -318,31 +318,41 @@ constexpr bool isnan(QuantityPoint<U, R> p) { | |||
| return std::isnan(p.in(U{})); | |||
| } | |||
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| namespace detail { | |||
| // Some compilers do not support lambdas in constexpr contexts, so we make a manual function object. | |||
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Should we update the comment about this being a C++17 thing, or is it the case that even with C++17, some compilers still don't support it.
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Good point! Addressed in #252.
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These have been
constexprcompatible since C++14. Mechanically, theway I did this was:
constexpr.constexprto pass (eithertweaking an existing test, or making a new one).
The biggest challenge was that our default compiler wouldn't accept our
lambda in a
constexprcontext. That feels like a bug, but in anycase, we were able to work around it by making a manual function object
with an explicitly
constexprcall operator.Fixes #244.