C++ to C Converter
Port C++ object-oriented code to C for embedded systems and legacy compatibility with AI-powered conversion. Transforms C++ classes to C structs with associated functions, eliminates exception handling for error-code patterns, and converts RAII patterns to explicit cleanup functions. Compiles C++ algorithms to pure C89/C99 for microcontrollers and platforms lacking C++ runtime support—enabling deployment on resource-constrained embedded targets.
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Issue Description
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How It Works
- Step 1: Paste your C++ source code including class hierarchies, method definitions, constructor/destructor logic, and STL container usage.
- Step 2: The AI analyzes C++ OOP patterns identifying classes for struct conversion, virtual functions for function pointer tables, and RAII patterns for manual cleanup.
- Step 3: Advanced transformation generates C code with structs replacing classes, explicit init/cleanup functions replacing constructors/destructors, and error codes replacing exceptions.
- Step 4: Download pure C code compatible with C89/C99 compilers for embedded systems, microcontrollers, and legacy platforms without C++ runtime dependencies.
C++ vs C: Language Comparison
| Feature | C++ | C |
|---|---|---|
| OOP Support | Classes, inheritance, virtual functions | Structs with function pointers |
| Exception Handling | try-catch-throw | Error return codes |
| Templates | Generic programming | Code duplication or void* |
| RAII | Automatic destructors | Manual cleanup functions |
| Standard Library | STL containers, algorithms | Manual implementations |
Code Conversion Examples
Example 1: Class to Struct with Functions
#include <string>
#include <cmath>
class Vector2D {
private:
double x, y;
public:
Vector2D(double x, double y) : x(x), y(y) {}
double magnitude() const {
return std::sqrt(x * x + y * y);
}
Vector2D operator+(const Vector2D& other) const {
return Vector2D(x + other.x, y + other.y);
}
void normalize() {
double mag = magnitude();
if (mag > 0) {
x /= mag;
y /= mag;
}
}
};
// Usage
Vector2D v1(3.0, 4.0);
Vector2D v2(1.0, 2.0);
Vector2D v3 = v1 + v2;
v3.normalize();#include <math.h>
typedef struct {
double x;
double y;
} Vector2D;
void Vector2D_init(Vector2D* v, double x, double y) {
v->x = x;
v->y = y;
}
double Vector2D_magnitude(const Vector2D* v) {
return sqrt(v->x * v->x + v->y * v->y);
}
void Vector2D_add(const Vector2D* v1, const Vector2D* v2, Vector2D* result) {
result->x = v1->x + v2->x;
result->y = v1->y + v2->y;
}
void Vector2D_normalize(Vector2D* v) {
double mag = Vector2D_magnitude(v);
if (mag > 0) {
v->x /= mag;
v->y /= mag;
}
}
// Usage
Vector2D v1, v2, v3;
Vector2D_init(&v1, 3.0, 4.0);
Vector2D_init(&v2, 1.0, 2.0);
Vector2D_add(&v1, &v2, &v3);
Vector2D_normalize(&v3);Key Changes:
C++ classes become C structs with associated functions. Constructors convert to initialization functions taking struct pointers. Methods become functions with struct pointers as first parameters (mimicking 'this'). Operator overloading (+) converts to explicit function calls (Vector2D_add). Const methods become functions taking const pointers. Private/public access modifiers disappear—C lacks encapsulation enforcement. The std::sqrt becomes C's math.h sqrt. Object instantiation becomes struct declaration plus init function call.
Example 2: RAII to Manual Resource Management
#include <fstream>
#include <vector>
#include <stdexcept>
class FileProcessor {
private:
std::ifstream file;
std::vector<std::string> lines;
public:
FileProcessor(const std::string& filename) {
file.open(filename);
if (!file.is_open()) {
throw std::runtime_error("Failed to open file");
}
}
~FileProcessor() {
if (file.is_open()) {
file.close();
}
}
void processLines() {
std::string line;
while (std::getline(file, line)) {
lines.push_back(line);
}
}
size_t getLineCount() const {
return lines.size();
}
};
// Usage (RAII handles cleanup automatically)
FileProcessor processor("data.txt");
processor.processLines();
size_t count = processor.getLineCount();#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct {
FILE* file;
char** lines;
size_t line_count;
size_t capacity;
} FileProcessor;
int FileProcessor_init(FileProcessor* fp, const char* filename) {
fp->file = fopen(filename, "r");
if (fp->file == NULL) {
return -1; // Error code instead of exception
}
fp->lines = NULL;
fp->line_count = 0;
fp->capacity = 0;
return 0; // Success
}
void FileProcessor_cleanup(FileProcessor* fp) {
if (fp->file != NULL) {
fclose(fp->file);
fp->file = NULL;
}
for (size_t i = 0; i < fp->line_count; i++) {
free(fp->lines[i]);
}
free(fp->lines);
}
int FileProcessor_processLines(FileProcessor* fp) {
char buffer[1024];
while (fgets(buffer, sizeof(buffer), fp->file) != NULL) {
// Grow array if needed
if (fp->line_count >= fp->capacity) {
fp->capacity = fp->capacity == 0 ? 10 : fp->capacity * 2;
fp->lines = (char**)realloc(fp->lines, fp->capacity * sizeof(char*));
}
fp->lines[fp->line_count] = strdup(buffer);
fp->line_count++;
}
return 0;
}
size_t FileProcessor_getLineCount(const FileProcessor* fp) {
return fp->line_count;
}
// Usage (manual cleanup required)
FileProcessor processor;
if (FileProcessor_init(&processor, "data.txt") == 0) {
FileProcessor_processLines(&processor);
size_t count = FileProcessor_getLineCount(&processor);
FileProcessor_cleanup(&processor); // Explicit cleanup!
}Key Changes:
C++'s RAII (Resource Acquisition Is Initialization) converts to explicit init/cleanup functions. Automatic destructors become manual cleanup calls—forgetting FileProcessor_cleanup causes resource leaks. Exceptions convert to error return codes checked by callers. STL vector becomes manual dynamic array management with realloc. Std::string becomes char* with strdup for copying. The ifstream file handle becomes FILE* pointer. This conversion exposes all the memory and resource management C++ hides, requiring careful manual tracking.
Frequently Asked Questions
Can I customize how classes are converted (methods vs function pointers)?
The converter generates structs with separate functions by default. Methods take struct pointers as the first parameter. For polymorphism, you can manually add vtable function pointers. The default approach balances simplicity and compatibility for embedded systems without C++ runtime support.
Is my C++ code sent to external servers?
Yes. AI conversion requires server-side LLM processing. Your C++ source is transmitted over HTTPS, converted, then discarded. We do not store code. For client-side conversion, manual rewriting is required.
What C++ features cannot be converted to C?
Exception handling (try/catch) has no C equivalent—error codes must replace exceptions. Multiple inheritance with virtual bases requires complex manual vtable setup. Template metaprogramming and constexpr compile-time evaluation must be pre-computed. The converter handles standard C++98/03 OOP patterns targeting C89/C99.