replace bit_cast with as_type

src/QuestScript.cc

@@ -1,9 +1,9 @@
 #include "QuestScript.hh"
 
 #include <stdint.h>
+#include <string.h>
 
 #include <array>
-#include <bit>
 #include <deque>
 #include <map>
 #include <phosg/Strings.hh>
@@ -17,6 +17,17 @@
 
 using namespace std;
 
+// bit_cast isn't in the standard place on macOS (it is apparently implicitly
+// included by resource_dasm, but newserv can be built without resource_dasm)
+// and I'm too lazy to go find the right header to include
+template <typename ToT, typename FromT>
+ToT as_type(const FromT& v) {
+  static_assert(sizeof(FromT) == sizeof(ToT), "types are not the same size");
+  ToT ret;
+  memcpy(&ret, &v, sizeof(ToT));
+  return ret;
+}
+
 static string format_and_indent_data(const void* data, size_t size, uint64_t start_address) {
   struct iovec iov;
   iov.iov_base = const_cast<void*>(data);
@@ -1199,7 +1210,7 @@ std::string disassemble_quest_script(const void* data, size_t size, GameVersion
                 case Type::FLOAT32: {
                   float v = cmd_r.get_f32l();
                   if (def->flags & QuestScriptOpcodeDefinition::Flag::PRESERVE_ARG_STACK) {
-                    arg_stack_values.emplace_back(ArgStackValue::Type::INT, bit_cast<uint32_t>(v));
+                    arg_stack_values.emplace_back(ArgStackValue::Type::INT, as_type<uint32_t>(v));
                   }
                   dasm_arg = string_printf("%g", v);
                   break;
@@ -1321,7 +1332,7 @@ std::string disassemble_quest_script(const void* data, size_t size, GameVersion
                         dasm_arg = string_printf("(float)r%" PRIu32, arg_value.as_int);
                         break;
                       case ArgStackValue::Type::INT:
-                        dasm_arg = string_printf("%g", bit_cast<float>(arg_value.as_int));
+                        dasm_arg = string_printf("%g", as_type<float>(arg_value.as_int));
                         break;
                       default:
                         dasm_arg = "/* invalid-type */";