[libcxx-commits] [libcxx] [libc++] Improve the test coverage for std::vector::emplace (PR #132440)

[Peng Liu via libcxx-commits]

================
@@ -38,7 +38,35 @@ struct Throws {
 };
 
 bool Throws::sThrows = false;
-#endif
+
+struct ThrowingMove {
+  TEST_CONSTEXPR ThrowingMove() : value(0), do_throw(false) {}
+  TEST_CONSTEXPR explicit ThrowingMove(int v) : value(v), do_throw(false) {}
+  TEST_CONSTEXPR explicit ThrowingMove(int v, bool do_throw) : value(v), do_throw(do_throw) {}
+
+  ThrowingMove(const ThrowingMove& rhs)        = default;
+  ThrowingMove& operator=(const ThrowingMove&) = default;
+
+  TEST_CONSTEXPR_CXX14 ThrowingMove(ThrowingMove&& rhs) : value(rhs.value), do_throw(rhs.do_throw) {
+    if (do_throw)
+      throw 1;
+  }
+  TEST_CONSTEXPR_CXX14 ThrowingMove& operator=(ThrowingMove&& rhs) {
+    value    = rhs.value;
+    do_throw = rhs.do_throw;
+    if (do_throw)
+      throw 1;
+    return *this;
+  }
----------------
winner245 wrote:

```suggestion
  TEST_CONSTEXPR_CXX26 ThrowingMove& operator=(ThrowingMove&& rhs) {
    value    = rhs.value;
    do_throw = rhs.do_throw;
    if (do_throw)
      throw 1;
    return *this;
  }
```

I don't think `throw` is supported by C++14 constexpr. I am not sure clang currently supports `throw` or not. But at least, we need to use `TEST_CONSTEXPR_CXX26`. 

https://github.com/llvm/llvm-project/pull/132440