Error when build cpp extension: expected constructor, destructor?

I’m not very good at C++. I’m trying to follow this cpp_extension_tutorial.

This is my cpp_file: lltm.cpp
and here is my

I can’t compile code. Here is error when i compile:

running install
running bdist_egg
running egg_info
writing lltm_cpp.egg-info/PKG-INFO
writing dependency_links to lltm_cpp.egg-info/dependency_links.txt
writing top-level names to lltm_cpp.egg-info/top_level.txt
reading manifest file 'lltm_cpp.egg-info/SOURCES.txt'
writing manifest file 'lltm_cpp.egg-info/SOURCES.txt'
installing library code to build/bdist.linux-x86_64/egg
running install_lib
running build_ext
building 'lltm_cpp' extension
x86_64-linux-gnu-gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O2 -Wall -g -fstack-protector-strong -Wformat -Werror=format-security -g -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC -I/usr/local/lib/python3.7/dist-packages/torch/include -I/usr/local/lib/python3.7/dist-packages/torch/include/torch/csrc/api/include -I/usr/local/lib/python3.7/dist-packages/torch/include/TH -I/usr/local/lib/python3.7/dist-packages/torch/include/THC -I/usr/include/python3.7m -c lltm.cpp -o build/temp.linux-x86_64-3.7/lltm.o -DTORCH_API_INCLUDE_EXTENSION_H -DTORCH_EXTENSION_NAME=lltm_cpp -D_GLIBCXX_USE_CXX11_ABI=0 -std=c++11
lltm.cpp:1:9: warning: #pragma once in main file
 #pragma once
lltm.cpp:95:17: error: expected constructor, destructor, or type conversion before ‘(’ token
 PYBNIND11_MODULE("lltm_cpp", m)
error: command 'x86_64-linux-gnu-gcc' failed with exit status 1

What is wrong with this code? How can i fix it?