Use std::lower_bound() in a couple places.

core/src/fxge/ge/fx_ge_fontmap.cpp

Index: core/src/fxge/ge/fx_ge_fontmap.cpp
diff --git a/core/src/fxge/ge/fx_ge_fontmap.cpp b/core/src/fxge/ge/fx_ge_fontmap.cpp
index b9850f85db810e7afc9638f522ce0d1ffe8a1015..06b58ea3abc89218be842397200844985c82b89f 100644
--- a/core/src/fxge/ge/fx_ge_fontmap.cpp
+++ b/core/src/fxge/ge/fx_ge_fontmap.cpp
@@ -4,6 +4,7 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
+#include <algorithm>
 #include <limits>
 #include <vector>
 
@@ -197,17 +198,17 @@ const struct FX_FontStyle {
     {"Bold", 4}, {"Italic", 6}, {"BoldItalic", 10}, {"Reg", 3}, {"Regular", 7},
 };
 
-const struct CHARSET_MAP {
-  uint8_t charset;
+const struct CODEPAGE_MAP {
   FX_WORD codepage;
+  uint8_t charset;
 } g_Codepage2CharsetTable[] = {
-    {1, 0},      {2, 42},     {254, 437},  {255, 850},  {222, 874},
-    {128, 932},  {134, 936},  {129, 949},  {136, 950},  {238, 1250},
-    {204, 1251}, {0, 1252},   {161, 1253}, {162, 1254}, {177, 1255},
-    {178, 1256}, {186, 1257}, {163, 1258}, {130, 1361}, {77, 10000},
-    {78, 10001}, {79, 10003}, {80, 10008}, {81, 10002}, {83, 10005},
-    {84, 10004}, {85, 10006}, {86, 10081}, {87, 10021}, {88, 10029},
-    {89, 10007},
+    {0, 1},      {42, 2},     {437, 254},  {850, 255},  {874, 222},
+    {932, 128},  {936, 134},  {949, 129},  {950, 136},  {1250, 238},
+    {1251, 204}, {1252, 0},   {1253, 161}, {1254, 162}, {1255, 177},
+    {1256, 178}, {1257, 186}, {1258, 163}, {1361, 130}, {10000, 77},
+    {10001, 78}, {10002, 81}, {10003, 79}, {10004, 84}, {10005, 83},
+    {10006, 85}, {10007, 89}, {10008, 80}, {10021, 87}, {10029, 88},
+    {10081, 86},
 };
 
 const FX_DWORD kTableNAME = FXDWORD_GET_MSBFIRST("name");
@@ -281,21 +282,15 @@ CFX_ByteString FPDF_LoadTableFromTT(FXSYS_FILE* pFile,
 }
 
 uint8_t GetCharsetFromCodePage(FX_WORD codepage) {
-  int32_t iEnd = sizeof(g_Codepage2CharsetTable) / sizeof(CHARSET_MAP) - 1;
-  FXSYS_assert(iEnd >= 0);
-  int32_t iStart = 0, iMid;
-  do {
-    iMid = (iStart + iEnd) / 2;
-    const CHARSET_MAP& cp = g_Codepage2CharsetTable[iMid];
-    if (codepage == cp.codepage) {
-      return cp.charset;
-    }
-    if (codepage < cp.codepage) {
-      iEnd = iMid - 1;
-    } else {
-      iStart = iMid + 1;
-    }
-  } while (iStart <= iEnd);
+  const CODEPAGE_MAP* pEnd =
+      g_Codepage2CharsetTable + FX_ArraySize(g_Codepage2CharsetTable);
+  const CODEPAGE_MAP* pCharmap =
+      std::lower_bound(g_Codepage2CharsetTable, pEnd, codepage,
+                       [](const CODEPAGE_MAP& charset, FX_WORD page) {
+                         return charset.codepage < page;
+                       });
+  if (pCharmap < pEnd && codepage == pCharmap->codepage)
+    return pCharmap->charset;
   return 1;
 }