fix compiling

- user `+` instead of stream operator to append data to a string
- use literal operator to convert C strings

src/address_validator/address_validator.cpp

@@ -207,7 +207,7 @@ int main(int argc, char *argv[])
 	gulps::inst().set_thread_tag("MAIN");
 
 	// We won't replace the custom output writer here, so just direct **our** errors to console
-	std::unique_ptr<gulps::gulps_output> out(new gulps::gulps_print_output(true, fmt::color:white));
+	std::unique_ptr<gulps::gulps_output> out(new gulps::gulps_print_output(true, fmt::color::white));
 	out->add_filter([](const gulps::message& msg) -> bool { return msg.cat_major == GULPS_CAT_MAJOR && msg.lvl == gulps::LEVEL_ERROR; });
 	gulps::inst().add_output(std::move(out));
 

src/common/gulps.hpp

@@ -50,6 +50,7 @@
 #include <list>
 #include <vector>
 #include "thdq.hpp"
+#include "string.hpp"
 #include <fmt/format.h>
 #include <fmt/time.h>
 

src/cryptonote_basic/cryptonote_basic_impl.cpp

@@ -323,7 +323,7 @@ bool get_account_address_from_str(address_parse_info &info, std::string const &s
 		break;
 */
 	default:
-		GULPS_ERROR("Wrong address prefix: " << prefix);
+		GULPS_ERROR("Wrong address prefix: "_s + std::to_string(prefix));
 		return false;
 	}