allow for Enum Value Aliases (#43)

Author: seanstone

src/spb-proto-compiler/dumper/json/dumper.cpp

@@ -20,6 +20,7 @@
 #include <cctype>
 #include <cstdint>
 #include <map>
+#include <set>
 #include <spb/json/deserialize.hpp>
 #include <sstream>
 #include <stdexcept>
@@ -213,10 +214,13 @@ void dump_cpp_serialize_value( std::ostream & stream, const proto_enum & my_enum
     stream << "void serialize_value( detail::ostream & stream, const " << full_name
            << " & value )\n{\n";
     stream << "\tswitch( value )\n\t{\n";
+    std::set<int32_t> numbers_taken;
     for( const auto & field : my_enum.fields )
     {
+        if (numbers_taken.contains(field.number)) continue;
         stream << "\tcase " << full_name << "::" << field.name
                << ":\n\t\treturn stream.serialize( \"" << field.name << "\"sv);\n";
+        numbers_taken.insert(field.number);
     }
     stream << "\tdefault:\n\t\tthrow std::system_error( std::make_error_code( "
               "std::errc::invalid_argument ) );\n";
@@ -273,9 +277,12 @@ void dump_cpp_deserialize_value( std::ostream & stream, const proto_enum & my_en
               "std::errc::invalid_argument ) );\n";
     stream << "\t\t},\n\t\t[&]( int32_t enum_int )\n\t\t{\n\t\t\tswitch( " << full_name
            << "( enum_int ) )\n\t\t\t{\n";
+    std::set<int32_t> numbers_taken;
     for( const auto & field : my_enum.fields )
     {
+        if (numbers_taken.contains(field.number)) continue;
         stream << "\t\t\tcase " << full_name << "::" << field.name << ":\n";
+        numbers_taken.insert(field.number);
     }
     stream << "\t\t\t\tvalue = " << full_name << "( enum_int );\n\t\t\t\treturn ;\n";
     stream << "\t\t\t}\n\t\t\tthrow std::system_error( std::make_error_code( "