Still more comments about strings

core/fxcrt/include/fx_string.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef CORE_FXCRT_INCLUDE_FX_STRING_H_
 #define CORE_FXCRT_INCLUDE_FX_STRING_H_
 
 #include <stdint.h>  // For intptr_t.
@@ skipping 16 matching lines @@
   CFX_ByteStringC() {
     m_Ptr = NULL;
     m_Length = 0;
   }
 
   CFX_ByteStringC(const uint8_t* ptr, FX_STRSIZE size) {
     m_Ptr = ptr;
     m_Length = size;
   }
 
+  // Deliberately implicit to avoid calling on every string literal.
   CFX_ByteStringC(const FX_CHAR* ptr) {
     m_Ptr = (const uint8_t*)ptr;
     m_Length = ptr ? FXSYS_strlen(ptr) : 0;
   }
 
+  // Deliberately implicit to avoid calling on every string literal.
   // |ch| must be an lvalue that outlives the the CFX_ByteStringC. However,
   // the use of char rvalues are not caught at compile time.  They are
   // implicitly promoted to CFX_ByteString (see below) and then the
   // CFX_ByteStringC is constructed from the CFX_ByteString via the alternate
   // constructor below. The CFX_ByteString then typically goes out of scope
   // and |m_Ptr| may be left pointing to invalid memory. Beware.
-  // TODO(tsepez): Mark single-argument string constructors as explicit.
   CFX_ByteStringC(FX_CHAR& ch) {
     m_Ptr = (const uint8_t*)&ch;
     m_Length = 1;
   }
 
   CFX_ByteStringC(const FX_CHAR* ptr, FX_STRSIZE len) {
     m_Ptr = (const uint8_t*)ptr;
     m_Length = (len == -1) ? FXSYS_strlen(ptr) : len;
   }
 
@@ skipping 291 matching lines @@
 
 class CFX_WideStringC {
  public:
   typedef FX_WCHAR value_type;
 
   CFX_WideStringC() {
     m_Ptr = NULL;
     m_Length = 0;
   }
 
+  // Deliberately implicit to avoid calling on every string literal.
   CFX_WideStringC(const FX_WCHAR* ptr) {
     m_Ptr = ptr;
     m_Length = ptr ? FXSYS_wcslen(ptr) : 0;
   }
 
+  // Deliberately implicit to avoid calling on every string literal.
+  // |ch| must be an lvalue that outlives the the CFX_WideStringC. However,
+  // the use of char rvalues are not caught at compile time.  They are
+  // implicitly promoted to CFX_WideString (see below) and then the
+  // CFX_WideStringC is constructed from the CFX_WideString via the alternate
+  // constructor below. The CFX_WideString then typically goes out of scope
+  // and |m_Ptr| may be left pointing to invalid memory. Beware.
   CFX_WideStringC(FX_WCHAR& ch) {
     m_Ptr = &ch;
     m_Length = 1;
   }
 
   CFX_WideStringC(const FX_WCHAR* ptr, FX_STRSIZE len) {
     m_Ptr = ptr;
     m_Length = (len == -1) ? FXSYS_wcslen(ptr) : len;
   }
 
@@ skipping 299 matching lines @@
 }
 
 FX_FLOAT FX_atof(const CFX_ByteStringC& str);
 inline FX_FLOAT FX_atof(const CFX_WideStringC& wsStr) {
   return FX_atof(FX_UTF8Encode(wsStr.c_str(), wsStr.GetLength()).c_str());
 }
 void FX_atonum(const CFX_ByteStringC& str, FX_BOOL& bInteger, void* pData);
 FX_STRSIZE FX_ftoa(FX_FLOAT f, FX_CHAR* buf);
 
 #endif  // CORE_FXCRT_INCLUDE_FX_STRING_H_