Here is a cool tip on how to use hashtag#LLM to build cross-language interfaces.
I did it with hashtag#ChatGPT-4o but it will probably work with others.<p>Here is my prompt:
I need to use following c++ class from python code:
class TestIt {
public:
std::string f1, f2;<p>std::string getf1() const { return f1; }
};<p>And here is what I get as output:
To use a C++ class from Python, you can use a tool like `pybind11`, which allows you to create Python bindings for C++ code. Here is a step-by-step guide to expose your `TestIt` class to Python:<p>### Step 1: Write the C++ Code<p>First, let's create a header file (`test_it.h`) and an implementation file (`test_it.cpp`) for your C++ class:<p>*test_it.h:*<p>```cpp
hashtag#ifndef TEST_IT_H
hashtag#define TEST_IT_H<p>hashtag#include <string><p>class TestIt {
public:
std::string f1, f2;<p>std::string getf1() const { return f1; }
};<p>hashtag#endif // TEST_IT_H
```<p>*test_it.cpp:*<p>```cpp
hashtag#include "test_it.h"<p>```<p>### Step 2: Write the pybind11 Binding Code<p>Create a new C++ file for the pybind11 bindings, say `bindings.cpp`:<p>*bindings.cpp:*<p>```cpp
hashtag#include <pybind11/pybind11.h>
hashtag#include <pybind11/stl.h>
hashtag#include "test_it.h"<p>namespace py = pybind11;<p>PYBIND11_MODULE(testit, m) {
py::class_<TestIt>(m, "TestIt")
.def(py::init<>()) // Bind the default constructor
.def_readwrite("f1", &TestIt::f1) // Bind the public member f1
.def_readwrite("f2", &TestIt::f2) // Bind the public member f2
.def("getf1", &TestIt::getf1); // Bind the getf1 method
}
```<p>### Step 3: Build the Python Module<p>To compile the code, you need to have `pybind11` installed and properly set up. You can install `pybind11` using pip:<p>```sh
pip install pybind11
```<p>Create a `CMakeLists.txt` file to handle the build process:<p>*CMakeLists.txt:*<p>```cmake
cmake_minimum_required(VERSION 3.10)
project(testit)<p>set(CMAKE_CXX_STANDARD 14)<p>find_package(pybind11 REQUIRED)<p>add_library(testit MODULE bindings.cpp test_it.cpp)
target_link_libraries(testit PRIVATE pybind11::module)
```<p>### Step 4: Compile the Module<p>Run the following commands to compile your module:<p>```sh
mkdir build
cd build
cmake ..
make
```<p>This will generate a shared library file (`testit.so` on Linux, `testit.pyd` on Windows) that you can import in Python.<p>### Step 5: Use the Module in Python<p>Finally, you can use your C++ class in Python:<p>*test.py:*<p>```python
import testit<p># Create an instance of TestIt
test_instance = testit.TestIt()<p># Set values for f1 and f2
test_instance.f1 = "Hello"
test_instance.f2 = "World"<p># Get the value of f1 using the method
print(test_instance.getf1()) # Output: Hello<p># Print the value of f2 directly
print(test_instance.f2) # Output: World
```<p>### Additional Notes<p>- The `pybind11` library should be correctly installed and discoverable by CMake.
- Adjust the `CMakeLists.txt` if you have additional include directories or dependencies.<p>By following these steps, you should be able to use your C++ class `TestIt` in Python seamlessly.