From a5882e9abe359ffc24a3233c3e2472f8b3e9b6f5 Mon Sep 17 00:00:00 2001
From: Marc Chevrier <marc.chevrier@gmail.com>
Date: Tue, 17 Mar 2026 16:02:16 +0100
Subject: [PATCH] cmext/algorithm: Fix return type of cm::keys and cm::values

---
 Tests/CMakeLib/testCMExtAlgorithm.cxx | 71 +++++++++++++++++++++++++++
 Utilities/std/cm/ranges               |  2 +-
 Utilities/std/cmext/algorithm         | 32 +++++++-----
 3 files changed, 91 insertions(+), 14 deletions(-)

diff --git a/Tests/CMakeLib/testCMExtAlgorithm.cxx b/Tests/CMakeLib/testCMExtAlgorithm.cxx
index 53b0302a09..0f00bd3ca4 100644
--- a/Tests/CMakeLib/testCMExtAlgorithm.cxx
+++ b/Tests/CMakeLib/testCMExtAlgorithm.cxx
@@ -1,5 +1,8 @@
 #include <iostream>
+#include <map>
 #include <memory>
+#include <string>
+#include <tuple>
 #include <utility>
 #include <vector>
 
@@ -107,11 +110,79 @@ void testAppend()
     }
   }
 }
+
+void testKeys()
+{
+  {
+    std::map<std::string, int> m{ { "one", 1 }, { "two", 2 } };
+    std::vector<std::string> ref{ "one", "two" };
+
+    auto res = cm::keys(m);
+    if (res != ref) {
+      ++failed;
+    }
+  }
+  {
+    std::map<int, int> m{ { 1, 1 }, { 2, 2 } };
+    std::vector<int> ref{ 1, 2 };
+
+    auto res = cm::keys(m);
+    if (res != ref) {
+      ++failed;
+    }
+  }
+  {
+    std::vector<std::tuple<std::string, int, int>> m;
+    m.emplace_back("one", 1, 10);
+    m.emplace_back("two", 2, 20);
+    std::vector<std::string> ref{ "one", "two" };
+
+    auto res = cm::keys(m);
+    if (res != ref) {
+      ++failed;
+    }
+  }
+}
+
+void testValues()
+{
+  {
+    std::map<std::string, int> m{ { "one", 1 }, { "two", 2 } };
+    std::vector<int> ref{ 1, 2 };
+
+    auto res = cm::values(m);
+    if (res != ref) {
+      ++failed;
+    }
+  }
+  {
+    std::map<int, std::string> m{ { 1, "one" }, { 2, "two" } };
+    std::vector<std::string> ref{ "one", "two" };
+
+    auto res = cm::values(m);
+    if (res != ref) {
+      ++failed;
+    }
+  }
+  {
+    std::vector<std::tuple<std::string, int, int>> m;
+    m.emplace_back("one", 1, 10);
+    m.emplace_back("two", 2, 20);
+    std::vector<int> ref{ 1, 2 };
+
+    auto res = cm::values(m);
+    if (res != ref) {
+      ++failed;
+    }
+  }
+}
 }
 
 int testCMExtAlgorithm(int /*unused*/, char* /*unused*/[])
 {
   testAppend();
+  testKeys();
+  testValues();
 
   return failed;
 }
diff --git a/Utilities/std/cm/ranges b/Utilities/std/cm/ranges
index 799399816e..54ab47b170 100644
--- a/Utilities/std/cm/ranges
+++ b/Utilities/std/cm/ranges
@@ -102,7 +102,7 @@ template <typename Range,
                             cm::is_tuple<2, typename Range::value_type>::value,
                           int> = 0>
 std::vector<typename std::tuple_element<1, typename Range::value_type>::type>
-keys(Range const& range)
+values(Range const& range)
 {
   using value_type =
     typename std::tuple_element<1, typename Range::value_type>::type;
diff --git a/Utilities/std/cmext/algorithm b/Utilities/std/cmext/algorithm
index 327a7721f1..2aa1ec5ff6 100644
--- a/Utilities/std/cmext/algorithm
+++ b/Utilities/std/cmext/algorithm
@@ -260,12 +260,13 @@ template <
 std::vector<typename Range::key_type> keys(Range const& range)
 {
 #if defined(CMake_HAVE_CXX_RANGES)
+  using key_type = typename Range::key_type;
+
 #  if __cplusplus >= 202302L || (defined(_MSVC_LANG) && _MSVC_LANG >= 202302L)
-  return std::vector<std::string_view>{ std::from_range,
-                                        std::views::keys(range) };
+  return std::vector<key_type>{ std::from_range, std::views::keys(range) };
 #  else
   auto view = std::views::keys(range);
-  return std::vector<std::string_view>{ view.begin(), view.end() };
+  return std::vector<key_type>{ view.begin(), view.end() };
 #  endif
 #else
   return cm::views::keys(range);
@@ -280,12 +281,13 @@ template <
 std::vector<typename Range::mapped_type> values(Range const& range)
 {
 #if defined(CMake_HAVE_CXX_RANGES)
+  using value_type = typename Range::mapped_type;
+
 #  if __cplusplus >= 202302L || (defined(_MSVC_LANG) && _MSVC_LANG >= 202302L)
-  return std::vector<std::string_view>{ std::from_range,
-                                        std::views::values(range) };
+  return std::vector<value_type>{ std::from_range, std::views::values(range) };
 #  else
   auto view = std::views::values(range);
-  return std::vector<std::string_view>{ view.begin(), view.end() };
+  return std::vector<value_type>{ view.begin(), view.end() };
 #  endif
 #else
   return cm::views::values(range);
@@ -301,12 +303,14 @@ std::vector<typename std::tuple_element<0, typename Range::value_type>::type>
 keys(Range const& range)
 {
 #if defined(CMake_HAVE_CXX_RANGES)
+  using key_type =
+    typename std::tuple_element<0, typename Range::value_type>::type;
+
 #  if __cplusplus >= 202302L || (defined(_MSVC_LANG) && _MSVC_LANG >= 202302L)
-  return std::vector<std::string_view>{ std::from_range,
-                                        std::views::keys(range) };
+  return std::vector<key_type>{ std::from_range, std::views::keys(range) };
 #  else
   auto view = std::views::keys(range);
-  return std::vector<std::string_view>{ view.begin(), view.end() };
+  return std::vector<key_type>{ view.begin(), view.end() };
 #  endif
 #else
   return cm::views::keys(range);
@@ -318,15 +322,17 @@ template <typename Range,
                             cm::is_tuple<2, typename Range::value_type>::value,
                           int> = 0>
 std::vector<typename std::tuple_element<1, typename Range::value_type>::type>
-keys(Range const& range)
+values(Range const& range)
 {
 #if defined(CMake_HAVE_CXX_RANGES)
+  using value_type =
+    typename std::tuple_element<1, typename Range::value_type>::type;
+
 #  if __cplusplus >= 202302L || (defined(_MSVC_LANG) && _MSVC_LANG >= 202302L)
-  return std::vector<std::string_view>{ std::from_range,
-                                        std::views::values(range) };
+  return std::vector<value_type>{ std::from_range, std::views::values(range) };
 #  else
   auto view = std::views::values(range);
-  return std::vector<std::string_view>{ view.begin(), view.end() };
+  return std::vector<value_type>{ view.begin(), view.end() };
 #  endif
 #else
   return cm::views::values(range);