[libcxx-commits] [libcxx] [libc++][ranges] optimize the performance of `ranges::starts_with` (PR #84570)

[Xiaoyang Liu via libcxx-commits]

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@@ -50,14 +54,36 @@ struct __fn {
       _Pred __pred   = {},
       _Proj1 __proj1 = {},
       _Proj2 __proj2 = {}) {
-    return __mismatch::__fn::__go(
+    if constexpr (sized_sentinel_for<_Sent1, _Iter1> && sized_sentinel_for<_Sent2, _Iter2>) {
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xiaoyang-sde wrote:

I manually inserted `return false` in each branch and verified that all branches are covered. Do we have a code coverage generator for `libc++` test cases?

https://github.com/llvm/llvm-project/pull/84570