Introduce Maps::transform_values()

1 files changed, 12 insertions, 0 deletions

diff --git a/toolsrc/include/vcpkg/base/util.h b/toolsrc/include/vcpkg/base/util.h
index c73345719..7266fbbc6 100644
--- a/toolsrc/include/vcpkg/base/util.h
+++ b/toolsrc/include/vcpkg/base/util.h
@@ -3,6 +3,7 @@
 #include <algorithm>
 #include <map>
 #include <mutex>
+#include <unordered_map>
 #include <utility>
 #include <vector>
 
@@ -29,6 +30,17 @@ namespace vcpkg::Util
         }
     }
 
+    namespace Maps
+    {
+        template<class K, class V1, class V2, class Func>
+        void transform_values(const std::unordered_map<K, V1>& container, std::unordered_map<K, V2>& output, Func func)
+        {
+            std::for_each(container.cbegin(), container.cend(), [&](const std::pair<const K, V1>& p) {
+                output[p.first] = func(p.second);
+            });
+        }
+    }
+
     template<class Cont, class Func>
     using FmapOut = decltype(std::declval<Func&>()(*begin(std::declval<Cont&>())));