[core] Use UTF-16 instead of UTF-32 for label features to avoid extra conversions and reduce in-memory size.

Continue to use uint32 as glyph ID to maintain Glyph PBF, even though we're only using 16 bits of that uint32.
Use std::codecvt instead of boost::unicode_iterator for UTF8->UTF16 conversions.

2 files changed, 2 insertions, 2 deletions

diff --git a/platform/default/mbgl/storage/offline_download.cpp b/platform/default/mbgl/storage/offline_download.cpp
index 9e2e11c86f..3edc75845c 100644
--- a/platform/default/mbgl/storage/offline_download.cpp
+++ b/platform/default/mbgl/storage/offline_download.cpp
@@ -184,7 +184,7 @@ void OfflineDownload::activateDownload() {
 
         if (!parser.glyphURL.empty()) {
             for (const auto& fontStack : parser.fontStacks()) {
-                for (uint32_t i = 0; i < GLYPH_RANGES_PER_FONT_STACK; i++) {
+                for (char16_t i = 0; i < GLYPH_RANGES_PER_FONT_STACK; i++) {
                     queueResource(Resource::glyphs(parser.glyphURL, fontStack, getGlyphRange(i * GLYPHS_PER_GLYPH_RANGE)));
                 }
             }
diff --git a/platform/default/string_stdlib.cpp b/platform/default/string_stdlib.cpp
index 90a75c1738..0e97fc54d5 100644
--- a/platform/default/string_stdlib.cpp
+++ b/platform/default/string_stdlib.cpp
@@ -1,10 +1,10 @@
 #include <mbgl/platform/platform.hpp>
-#include <mbgl/util/utf.hpp>
 #define NU_WITH_TOUPPER
 #define NU_WITH_TOLOWER
 #define NU_WITH_UTF8_WRITER
 #include <libnu/libnu.h>
 #include <cstring>
+#include <sstream>
 
 namespace mbgl { namespace platform {