diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td index 7a130c434e73ced..fbbfc4acdf391ef 100644 --- a/clang/include/clang/Basic/AttrDocs.td +++ b/clang/include/clang/Basic/AttrDocs.td @@ -3702,20 +3702,32 @@ user-declared functions. For example: .. code-block:: c++ + #include + #include + + using namespace std::literals; + // Returns m[key] if key is present, or default_value if not. template const U &get_or_default(const std::map &m [[clang::lifetimebound]], const T &key, /* note, not lifetimebound */ - const U &default_value [[clang::lifetimebound]]); + const U &default_value [[clang::lifetimebound]]) { + if (auto iter = m.find(key); iter != m.end()) return iter->second; + else return default_value; + } - std::map m; - // warning: temporary "bar"s that might be bound to local reference 'val' - // will be destroyed at the end of the full-expression - const std::string &val = get_or_default(m, "foo"s, "bar"s); + int main() { + std::map m; + // warning: temporary bound to local reference 'val1' will be destroyed + // at the end of the full-expression + const std::string &val1 = get_or_default(m, "foo"s, "bar"s); - // No warning in this case. - std::string def_val = "bar"s; - const std::string &val = get_or_default(m, "foo"s, def_val); + // No warning in this case. + std::string def_val = "bar"s; + const std::string &val2 = get_or_default(m, "foo"s, def_val); + + return 0; + } The attribute can be applied to the implicit ``this`` parameter of a member function by writing the attribute after the function type: