Fix v141 warnings in websocketpp

Author: ras0219-msft

Release/libs/websocketpp/websocketpp/frame.hpp

@@ -235,17 +235,17 @@ struct basic_header {
 /// The variable size component of a WebSocket frame header
 struct extended_header {
     extended_header() {
-        std::fill_n(this->bytes.begin(), MAX_EXTENDED_HEADER_LENGTH, 0x00);
+        std::fill_n(this->bytes.begin(), MAX_EXTENDED_HEADER_LENGTH, static_cast<uint8_t>(0x00));
     }
 
     extended_header(uint64_t payload_size) {
-        std::fill_n(this->bytes.begin(), MAX_EXTENDED_HEADER_LENGTH, 0x00);
+        std::fill_n(this->bytes.begin(), MAX_EXTENDED_HEADER_LENGTH, static_cast<uint8_t>(0x00));
 
         copy_payload(payload_size);
     }
 
     extended_header(uint64_t payload_size, uint32_t masking_key) {
-        std::fill_n(this->bytes.begin(), MAX_EXTENDED_HEADER_LENGTH, 0x00);
+        std::fill_n(this->bytes.begin(), MAX_EXTENDED_HEADER_LENGTH, static_cast<uint8_t>(0x00));
 
         // Copy payload size
         int offset = copy_payload(payload_size);

Release/libs/websocketpp/websocketpp/impl/utilities_impl.hpp

@@ -36,7 +36,7 @@ namespace utility {
 
 inline std::string to_lower(std::string const & in) {
     std::string out = in;
-    std::transform(out.begin(),out.end(),out.begin(),::tolower);
+    std::transform(out.begin(), out.end(), out.begin(), [](char ch) { return static_cast<char>(::tolower(ch)); });
     return out;
 }
 

Release/libs/websocketpp/websocketpp/processors/hybi00.hpp

@@ -421,7 +421,7 @@ class hybi00 : public processor<config> {
             memcpy(result, reinterpret_cast<char*>(&num), 4);
 #endif
         } else {
-            std::fill(result,result+4,0);
+            std::fill(result,result+4, static_cast<char>(0));
         }
     }
 

Release/libs/websocketpp/websocketpp/processors/hybi13.hpp

@@ -464,7 +464,7 @@ class hybi13 : public processor<config> {
         std::fill(
             m_extended_header.bytes.begin(),
             m_extended_header.bytes.end(),
-            0x00
+            static_cast<uint8_t>(0x00)
         );
     }