From b3220cc302ccaa3b0e0859045a83d945f838371a Mon Sep 17 00:00:00 2001
From: Twan van Laarhoven <twanvl@gmail.com>
Date: Sat, 3 Jul 2021 23:11:35 +0200
Subject: [PATCH] Add std::hash instance for String (for wxWidgets < 3.1)

---
 src/util/string.hpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/util/string.hpp b/src/util/string.hpp
index 48020bba..548314f6 100644
--- a/src/util/string.hpp
+++ b/src/util/string.hpp
@@ -33,6 +33,17 @@ inline wxStdString const& toStdString(String const& s) {
   #endif
 }
 
+#if wxVERSION_NUMBER < 3100
+// wxWidgets 3.1.0 added this specialization
+namespace std {
+  template<> struct hash<String> {
+    size_t operator()(String const& s) const {
+      return std::hash<std::wstring>()(s.ToStdWstring());
+    }
+  };
+} //
+#endif
+
 // ----------------------------------------------------------------------------- : Unicode
 
 /// u if UNICODE is defined, a otherwise