Fix compiling if not include size_t

example/example.cpp

@@ -24,7 +24,6 @@
 // Simple Example.
 
 #include <iostream>
-#include <cstdint>
 #include <nameof.hpp>
 
 struct SomeStruct {

src/nameof.hpp

@@ -22,6 +22,7 @@
 // SOFTWARE.
 
 #pragma once
+#include <cstddef>
 
 inline constexpr const char* template_nameof_(const char* name, size_t length) {
   return length == 0 ? name