added std::string conversion for fc::string

include/fc/string.hpp

@@ -2,6 +2,25 @@
 #define _FC_STRING_HPP_
 #include <stdint.h>
 
+
+/**
+ *  There is debate about whether doing this is 'standard conforming', but 
+ *  it works everywhere and enables the purpose of this library which is to 
+ *  accelerate compiles while maintaining compatability.
+ */
+namespace std {
+  template<class Char>
+  struct char_traits;
+
+  template<class T>
+  struct allocator;
+
+  template<class Char, class Traits, class Allocator>
+  struct basic_string;
+
+  typedef basic_string<char, char_traits<char>, allocator<char> > string;
+}
+
 namespace fc {
   /**
    *  Including <string> results in 4000 lines of code
@@ -17,6 +36,8 @@ namespace fc {
       typedef const char* const_iterator;
 
       string();
+      string( const std::string& s );
+      string( std::string&& s );
       string( const string& c );
       string( string&& c );
       string( const char* c );
@@ -24,6 +45,9 @@ namespace fc {
       string( const_iterator b, const_iterator e );
       ~string();
 
+      operator std::string&();
+      operator const std::string&()const;
+
       iterator begin();
       iterator end();
 

src/string.cpp

@@ -44,7 +44,21 @@ namespace fc  {
     static_assert( sizeof(my) >= sizeof(std::string), "failed to reserve enough space" );
     new (this) std::string(b,e);
   }
+  string::string( const std::string& s ) {
+    static_assert( sizeof(my) >= sizeof(std::string), "failed to reserve enough space" );
+    new (this) std::string(s);
+  }
+  string::string( std::string&& s ) {
+    static_assert( sizeof(my) >= sizeof(std::string), "failed to reserve enough space" );
+    new (this) std::string(fc::move(s));
+  }
 
+  string::operator std::string&() {
+     return *reinterpret_cast<std::string*>(this);
+  }
+  string::operator const std::string&()const {
+     return *reinterpret_cast<const std::string*>(this);
+  }
 
   string::~string() {
     ::detail::destroy( this );