add vector_fread

buffer.h

 #ifndef CORE_BUFFER_H
 #define CORE_BUFFER_H
 
+#include <cstdio>
 #include <cstring>
 #include <vector>
 
@@ -34,4 +35,11 @@ inline void vector_write(std::vector<unsigned char>& buffer, T value) {
 	vector_write_block(buffer, &value, sizeof(T));
 }
 
+inline void vector_fread(std::vector<unsigned char>& buffer, FILE* fp) {
+	unsigned char temp[4096]{};
+	while (size_t len = std::fread(temp, 1, sizeof temp, fp))
+		vector_write_block(buffer, temp, len);
+	std::fclose(fp);
+}
+
 #endif // !CORE_BUFFER_H