2 files changed, 21 insertions, 10 deletions
diff --git a/src/DBCS.cxx b/src/DBCS.cxx
index f4aaff433..f92b7a5a9 100644
--- a/src/DBCS.cxx
+++ b/src/DBCS.cxx
@@ -7,8 +7,10 @@
 
 #include <cstdint>
 
+#include <vector>
 #include <array>
 #include <map>
+#include <algorithm>
 
 #include "DBCS.h"
 
@@ -99,21 +101,31 @@ bool IsDBCSValidSingleByte(int codePage, int ch) noexcept {
 
 // NOLINTEND(*-magic-numbers)
 
-using CodePageToFoldMap = std::map<int, FoldMap>;
+namespace {
+
+struct CodePageFoldMap {
+	int codePage = 0;
+	FoldMap foldMap;
+	explicit CodePageFoldMap(int codePage_) noexcept : codePage {codePage_} {}
+};
+
+using CodePageToFoldMap = std::vector<CodePageFoldMap>;
 CodePageToFoldMap cpToFoldMap;
 
-bool DBCSHasFoldMap(int codePage) {
-	const CodePageToFoldMap::const_iterator it = cpToFoldMap.find(codePage);
-	return it != cpToFoldMap.end();
 }
 
-FoldMap *DBCSGetMutableFoldMap(int codePage) {
-	// Constructs if needed
-	return &cpToFoldMap[codePage];
+FoldMap *DBCSCreateFoldMap(int codePage) {
+	cpToFoldMap.emplace_back(codePage);
+	return &(cpToFoldMap.back().foldMap);
 }
 
 const FoldMap *DBCSGetFoldMap(int codePage) {
-	return &cpToFoldMap[codePage];
+	const CodePageToFoldMap::iterator it = std::find_if(cpToFoldMap.begin(), cpToFoldMap.end(),
+		[codePage](const CodePageFoldMap &cpfm) -> bool {return cpfm.codePage == codePage; });
+	if (it != cpToFoldMap.end()) {
+		return &(it->foldMap);
+	}
+	return nullptr;
 }
 
 }
diff --git a/src/DBCS.h b/src/DBCS.h
index 2b66db261..466d70ec7 100644
--- a/src/DBCS.h
+++ b/src/DBCS.h
@@ -41,8 +41,7 @@ struct DBCSPair {
 };
 using FoldMap = std::array<DBCSPair, 0x8000>;
 
-bool DBCSHasFoldMap(int codePage);
-FoldMap *DBCSGetMutableFoldMap(int codePage);
+FoldMap *DBCSCreateFoldMap(int codePage);
 const FoldMap *DBCSGetFoldMap(int codePage);
 
 }