Cool method to use LLM to build cross language interfaces
4 points by vadiml 11 months ago | 0 commentsHere is my prompt: I need to use following c++ class from python code: class TestIt { public: std::string f1, f2;
std::string getf1() const { return f1; } };
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:
### Step 1: Write the C++ Code
First, let's create a header file (`test_it.h`) and an implementation file (`test_it.cpp`) for your C++ class:
*test_it.h:*
```cpp hashtag#ifndef TEST_IT_H hashtag#define TEST_IT_H
hashtag#include <string>
class TestIt { public: std::string f1, f2;
std::string getf1() const { return f1; } };
hashtag#endif // TEST_IT_H ```
*test_it.cpp:*
```cpp hashtag#include "test_it.h"
```
### Step 2: Write the pybind11 Binding Code
Create a new C++ file for the pybind11 bindings, say `bindings.cpp`:
*bindings.cpp:*
```cpp hashtag#include <pybind11/pybind11.h> hashtag#include <pybind11/stl.h> hashtag#include "test_it.h"
namespace py = pybind11;
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 } ```
### Step 3: Build the Python Module
To compile the code, you need to have `pybind11` installed and properly set up. You can install `pybind11` using pip:
```sh pip install pybind11 ```
Create a `CMakeLists.txt` file to handle the build process:
*CMakeLists.txt:*
```cmake cmake_minimum_required(VERSION 3.10) project(testit)
set(CMAKE_CXX_STANDARD 14)
find_package(pybind11 REQUIRED)
add_library(testit MODULE bindings.cpp test_it.cpp) target_link_libraries(testit PRIVATE pybind11::module) ```
### Step 4: Compile the Module
Run the following commands to compile your module:
```sh mkdir build cd build cmake .. make ```
This will generate a shared library file (`testit.so` on Linux, `testit.pyd` on Windows) that you can import in Python.
### Step 5: Use the Module in Python
Finally, you can use your C++ class in Python:
*test.py:*
```python import testit
# Create an instance of TestIt test_instance = testit.TestIt()
# Set values for f1 and f2 test_instance.f1 = "Hello" test_instance.f2 = "World"
# Get the value of f1 using the method print(test_instance.getf1()) # Output: Hello
# Print the value of f2 directly print(test_instance.f2) # Output: World ```
### Additional Notes
- The `pybind11` library should be correctly installed and discoverable by CMake. - Adjust the `CMakeLists.txt` if you have additional include directories or dependencies.
By following these steps, you should be able to use your C++ class `TestIt` in Python seamlessly.