[PATCH] D142606: Lazyly initialize uncommon toolchain detector

Sun Feb 5 02:05:41 PST 2023

serge-sans-paille added inline comments.

================
Comment at: clang/lib/Driver/ToolChains/LazyDetector.h:26
+
+  mutable std::optional<T> Detector;
+
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zero9178 wrote:
> serge-sans-paille wrote:
> > zero9178 wrote:
> > > Any reason this is `mutable`? I don't see it being used a non-const way in a const method
> > yeah, `T const *operator->() const` updates the optional by actually creating the value. (`std::optional::empalce` is not const)
> Your `T const *operator->() const` method does not do so, `T *operator->()` does, which is non-const and hence can call `emplace` without issues. 
> So as far as C++ goes it is not required. 
gotcha :-)

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D142606/new/

https://reviews.llvm.org/D142606