[libcxx-commits] [libcxx] [libc++][flat_map] Applied `[[nodiscard]]` (PR #169453)
Hristo Hristov via libcxx-commits
libcxx-commits at lists.llvm.org
Mon Nov 24 21:56:03 PST 2025
https://github.com/H-G-Hristov updated https://github.com/llvm/llvm-project/pull/169453
>From a3244d870b3377300accb2a712e95359a88e8587 Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm at gmail.com>
Date: Tue, 25 Nov 2025 06:41:00 +0200
Subject: [PATCH] [libc++][flat_map] Applied `[[nodiscard]]`
`[[nodiscard]]` should be applied to functions where discarding the return value is most likely a correctness issue.
- https://libcxx.llvm.org/CodingGuidelines.html#apply-nodiscard-where-relevant
---
libcxx/include/__flat_map/flat_map.h | 99 +++++++++--------
.../diagnostics/flat_map.nodiscard.verify.cpp | 100 +++++++++++++++++-
.../index_transparent.pass.cpp | 2 +-
3 files changed, 151 insertions(+), 50 deletions(-)
diff --git a/libcxx/include/__flat_map/flat_map.h b/libcxx/include/__flat_map/flat_map.h
index 159e652e1a326..d3c3e0fab3e03 100644
--- a/libcxx/include/__flat_map/flat_map.h
+++ b/libcxx/include/__flat_map/flat_map.h
@@ -409,41 +409,45 @@ class flat_map {
}
// iterators
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator begin() noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator begin() noexcept {
return iterator(__containers_.keys.begin(), __containers_.values.begin());
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator begin() const noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator begin() const noexcept {
return const_iterator(__containers_.keys.begin(), __containers_.values.begin());
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator end() noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator end() noexcept {
return iterator(__containers_.keys.end(), __containers_.values.end());
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator end() const noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator end() const noexcept {
return const_iterator(__containers_.keys.end(), __containers_.values.end());
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 reverse_iterator rbegin() noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 reverse_iterator rbegin() noexcept {
return reverse_iterator(end());
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reverse_iterator rbegin() const noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reverse_iterator rbegin() const noexcept {
return const_reverse_iterator(end());
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 reverse_iterator rend() noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 reverse_iterator rend() noexcept {
return reverse_iterator(begin());
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reverse_iterator rend() const noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reverse_iterator rend() const noexcept {
return const_reverse_iterator(begin());
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator cbegin() const noexcept { return begin(); }
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator cend() const noexcept { return end(); }
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reverse_iterator crbegin() const noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator cbegin() const noexcept {
+ return begin();
+ }
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator cend() const noexcept {
+ return end();
+ }
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reverse_iterator crbegin() const noexcept {
return const_reverse_iterator(end());
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reverse_iterator crend() const noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reverse_iterator crend() const noexcept {
return const_reverse_iterator(begin());
}
@@ -452,22 +456,22 @@ class flat_map {
return __containers_.keys.empty();
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 size_type size() const noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 size_type size() const noexcept {
return __containers_.keys.size();
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 size_type max_size() const noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 size_type max_size() const noexcept {
return std::min<size_type>(__containers_.keys.max_size(), __containers_.values.max_size());
}
// [flat.map.access], element access
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 mapped_type& operator[](const key_type& __x)
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 mapped_type& operator[](const key_type& __x)
requires is_constructible_v<mapped_type>
{
return try_emplace(__x).first->second;
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 mapped_type& operator[](key_type&& __x)
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 mapped_type& operator[](key_type&& __x)
requires is_constructible_v<mapped_type>
{
return try_emplace(std::move(__x)).first->second;
@@ -476,11 +480,11 @@ class flat_map {
template <class _Kp>
requires(__is_compare_transparent && is_constructible_v<key_type, _Kp> && is_constructible_v<mapped_type> &&
!is_convertible_v<_Kp &&, const_iterator> && !is_convertible_v<_Kp &&, iterator>)
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 mapped_type& operator[](_Kp&& __x) {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 mapped_type& operator[](_Kp&& __x) {
return try_emplace(std::forward<_Kp>(__x)).first->second;
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 mapped_type& at(const key_type& __x) {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 mapped_type& at(const key_type& __x) {
auto __it = find(__x);
if (__it == end()) {
std::__throw_out_of_range("flat_map::at(const key_type&): Key does not exist");
@@ -488,7 +492,7 @@ class flat_map {
return __it->second;
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const mapped_type& at(const key_type& __x) const {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const mapped_type& at(const key_type& __x) const {
auto __it = find(__x);
if (__it == end()) {
std::__throw_out_of_range("flat_map::at(const key_type&) const: Key does not exist");
@@ -498,7 +502,7 @@ class flat_map {
template <class _Kp>
requires __is_compare_transparent
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 mapped_type& at(const _Kp& __x) {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 mapped_type& at(const _Kp& __x) {
auto __it = find(__x);
if (__it == end()) {
std::__throw_out_of_range("flat_map::at(const K&): Key does not exist");
@@ -508,7 +512,7 @@ class flat_map {
template <class _Kp>
requires __is_compare_transparent
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const mapped_type& at(const _Kp& __x) const {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const mapped_type& at(const _Kp& __x) const {
auto __it = find(__x);
if (__it == end()) {
std::__throw_out_of_range("flat_map::at(const K&) const: Key does not exist");
@@ -753,116 +757,121 @@ class flat_map {
}
// observers
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 key_compare key_comp() const { return __compare_; }
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 value_compare value_comp() const {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 key_compare key_comp() const { return __compare_; }
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 value_compare value_comp() const {
return value_compare(__compare_);
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const key_container_type& keys() const noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const key_container_type& keys() const noexcept {
return __containers_.keys;
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const mapped_container_type& values() const noexcept {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const mapped_container_type&
+ values() const noexcept {
return __containers_.values;
}
// map operations
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator find(const key_type& __x) {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator find(const key_type& __x) {
return __find_impl(*this, __x);
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator find(const key_type& __x) const {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator find(const key_type& __x) const {
return __find_impl(*this, __x);
}
template <class _Kp>
requires __is_compare_transparent
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator find(const _Kp& __x) {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator find(const _Kp& __x) {
return __find_impl(*this, __x);
}
template <class _Kp>
requires __is_compare_transparent
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator find(const _Kp& __x) const {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator find(const _Kp& __x) const {
return __find_impl(*this, __x);
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 size_type count(const key_type& __x) const {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 size_type count(const key_type& __x) const {
return contains(__x) ? 1 : 0;
}
template <class _Kp>
requires __is_compare_transparent
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 size_type count(const _Kp& __x) const {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 size_type count(const _Kp& __x) const {
return contains(__x) ? 1 : 0;
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 bool contains(const key_type& __x) const {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 bool contains(const key_type& __x) const {
return find(__x) != end();
}
template <class _Kp>
requires __is_compare_transparent
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 bool contains(const _Kp& __x) const {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 bool contains(const _Kp& __x) const {
return find(__x) != end();
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator lower_bound(const key_type& __x) {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator lower_bound(const key_type& __x) {
return __lower_bound<iterator>(*this, __x);
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator lower_bound(const key_type& __x) const {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator
+ lower_bound(const key_type& __x) const {
return __lower_bound<const_iterator>(*this, __x);
}
template <class _Kp>
requires __is_compare_transparent
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator lower_bound(const _Kp& __x) {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator lower_bound(const _Kp& __x) {
return __lower_bound<iterator>(*this, __x);
}
template <class _Kp>
requires __is_compare_transparent
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator lower_bound(const _Kp& __x) const {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator lower_bound(const _Kp& __x) const {
return __lower_bound<const_iterator>(*this, __x);
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator upper_bound(const key_type& __x) {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator upper_bound(const key_type& __x) {
return __upper_bound<iterator>(*this, __x);
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator upper_bound(const key_type& __x) const {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator
+ upper_bound(const key_type& __x) const {
return __upper_bound<const_iterator>(*this, __x);
}
template <class _Kp>
requires __is_compare_transparent
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator upper_bound(const _Kp& __x) {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator upper_bound(const _Kp& __x) {
return __upper_bound<iterator>(*this, __x);
}
template <class _Kp>
requires __is_compare_transparent
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator upper_bound(const _Kp& __x) const {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator upper_bound(const _Kp& __x) const {
return __upper_bound<const_iterator>(*this, __x);
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 pair<iterator, iterator> equal_range(const key_type& __x) {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 pair<iterator, iterator>
+ equal_range(const key_type& __x) {
return __equal_range_impl(*this, __x);
}
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 pair<const_iterator, const_iterator>
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 pair<const_iterator, const_iterator>
equal_range(const key_type& __x) const {
return __equal_range_impl(*this, __x);
}
template <class _Kp>
requires __is_compare_transparent
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 pair<iterator, iterator> equal_range(const _Kp& __x) {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 pair<iterator, iterator>
+ equal_range(const _Kp& __x) {
return __equal_range_impl(*this, __x);
}
template <class _Kp>
requires __is_compare_transparent
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 pair<const_iterator, const_iterator>
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 pair<const_iterator, const_iterator>
equal_range(const _Kp& __x) const {
return __equal_range_impl(*this, __x);
}
diff --git a/libcxx/test/libcxx/diagnostics/flat_map.nodiscard.verify.cpp b/libcxx/test/libcxx/diagnostics/flat_map.nodiscard.verify.cpp
index 79b943b790d04..389ec2f91e0ba 100644
--- a/libcxx/test/libcxx/diagnostics/flat_map.nodiscard.verify.cpp
+++ b/libcxx/test/libcxx/diagnostics/flat_map.nodiscard.verify.cpp
@@ -6,15 +6,107 @@
//
//===----------------------------------------------------------------------===//
-// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// REQUIRES: std-at-least-c++23
// <flat_map>
// [[nodiscard]] bool empty() const noexcept;
#include <flat_map>
+#include <utility>
-void f() {
- std::flat_map<int, int> c;
- c.empty(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+template <typename T>
+struct TransparentKey {
+ T t;
+
+ constexpr explicit operator T() const { return t; }
+};
+
+struct TransparentCompare {
+ using is_transparent = void; // This makes the comparator transparent
+
+ template <typename T>
+ constexpr bool operator()(const T& t, const TransparentKey<T>& transparent) const {
+ return t < transparent.t;
+ }
+
+ template <typename T>
+ constexpr bool operator()(const TransparentKey<T>& transparent, const T& t) const {
+ return transparent.t < t;
+ }
+
+ template <typename T>
+ constexpr bool operator()(const T& t1, const T& t2) const {
+ return t1 < t2;
+ }
+};
+
+void test() {
+ std::flat_map<int, int, TransparentCompare> fm;
+ const std::flat_map<int, int, TransparentCompare> cfm{};
+
+ fm.begin(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.begin(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.end(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.end(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.rbegin(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.rbegin(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.rend(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.rend(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.begin(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.cend(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.crbegin(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.crend(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+ fm.empty(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.size(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.max_size(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+ fm.empty(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+ int key = 0;
+ TransparentKey<int> tkey;
+
+ std::flat_map<int, int> nfm;
+ nfm[key]; // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm[std::move(key)]; // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm[std::move(tkey)]; // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+ fm.at(key); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.at(key); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.at(tkey); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.at(tkey); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+ fm.key_comp(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.value_comp(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.keys(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.values(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+ fm.find(key); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.find(key); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.find(tkey); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.find(tkey); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+ fm.count(key); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.count(tkey); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+ fm.contains(key); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.contains(key); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.contains(tkey); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.contains(tkey); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+ fm.lower_bound(key); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.lower_bound(key); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.lower_bound(tkey); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.lower_bound(tkey); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+ fm.upper_bound(key); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.upper_bound(key); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.upper_bound(tkey); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.upper_bound(tkey); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+ fm.equal_range(key); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.equal_range(key); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ fm.equal_range(tkey); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ cfm.equal_range(tkey); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
}
diff --git a/libcxx/test/std/containers/container.adaptors/flat.map/flat.map.access/index_transparent.pass.cpp b/libcxx/test/std/containers/container.adaptors/flat.map/flat.map.access/index_transparent.pass.cpp
index e8ea20b345e34..98629364654b6 100644
--- a/libcxx/test/std/containers/container.adaptors/flat.map/flat.map.access/index_transparent.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/flat.map/flat.map.access/index_transparent.pass.cpp
@@ -97,7 +97,7 @@ constexpr bool test() {
TransparentComparator c(transparent_used);
std::flat_map<int, int, TransparentComparator> m(std::sorted_unique, {{1, 1}, {2, 2}, {3, 3}}, c);
assert(!transparent_used);
- m[ConvertibleTransparent<int>{3}];
+ (void)m[ConvertibleTransparent<int>{3}];
assert(transparent_used);
}
{
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