chore: make #4587 use proper cpp17 feature macro (#4592)

Skylion007 · web-flow · commit 66f12df03b33 · 2023-03-27T10:59:56.000-04:00
diff --git a/include/pybind11/detail/descr.h b/include/pybind11/detail/descr.h
@@ -143,7 +143,7 @@ constexpr descr<N, Ts...> concat(const descr<N, Ts...> &descr) {
     return descr;
 }
 
-#if defined(PYBIND11_CPP17)
+#ifdef __cpp_fold_expressions
 template <size_t N1, size_t N2, typename... Ts1, typename... Ts2>
 constexpr descr<N1 + N2 + 2, Ts1..., Ts2...> operator,(const descr<N1, Ts1...> &a,
                                                        const descr<N2, Ts2...> &b) {

Original file line number	Diff line number	Diff line change
`@@ -143,7 +143,7 @@ constexpr descr<N, Ts...> concat(const descr<N, Ts...> &descr) {`
`143`	`143`	`return descr;`
`144`	`144`	`}`
`145`	`145`
`146`		`-#if defined(PYBIND11_CPP17)`
	`146`	`+#ifdef __cpp_fold_expressions`
`147`	`147`	`template <size_t N1, size_t N2, typename... Ts1, typename... Ts2>`
`148`	`148`	`constexpr descr<N1 + N2 + 2, Ts1..., Ts2...> operator,(const descr<N1, Ts1...> &a,`
`149`	`149`	`const descr<N2, Ts2...> &b) {`