Adding is_utf8 call and making enum_type cast explicit

include/fc/crypto/sha224.hpp

@@ -1,6 +1,7 @@
 #pragma once
 #include <unordered_map>
 #include <fc/fwd.hpp>
+#include <fc/io/raw_fwd.hpp>
 #include <fc/string.hpp>
 
 namespace fc
@@ -24,7 +25,7 @@ class sha224
     static sha224 hash( const T& t ) 
     { 
       sha224::encoder e; 
-      e << t; 
+      fc::raw::pack(e,t);
       return e.result(); 
     } 
 

include/fc/io/enum_type.hpp

@@ -17,7 +17,7 @@ namespace fc
       
       enum_type(){}
       
-      operator IntType()const     { return static_cast<IntType>(value);    }
+      explicit operator IntType()const     { return static_cast<IntType>(value);    }
       operator EnumType()const    { return value;                          }
       operator std::string()const { return fc::reflector<EnumType>::to_string(value); }
       

include/fc/utf8.hpp

@@ -8,6 +8,8 @@
 namespace fc
 {
 
+bool is_utf8( const std::string& str );
+
 /** Decodes utf 8 std::string into unicode string.
     @param input   - input string to be decoded and stored in 'storage'
     @param storage - buffer for converted text. Cannot be nullptr.

src/utf8.cpp

@@ -6,17 +6,21 @@
 
 #include <assert.h>
 
-namespace fc
+namespace fc {
-{
 
-void decodeUtf8(const std::string& input, std::wstring* storage)
+   bool is_utf8( const std::string& str )
+   {
+      return utf8::is_valid( str.begin(), str.end() );
+   }
+
+   void decodeUtf8(const std::string& input, std::wstring* storage)
    {
      assert(storage != nullptr);
 
      utf8::utf8to32(input.begin(), input.end(), std::back_inserter(*storage));
    }
 
-void encodeUtf8(const std::wstring& input, std::string* storage)
+   void encodeUtf8(const std::wstring& input, std::string* storage)
    {
      assert(storage != nullptr);