malloc

#include <iostream>
#include "stdint.h"

typedef struct {
    uint16_t param_count;
    uint16_t result_count;
    uint16_t param_cell_num;
    uint16_t ret_cell_num;
    /* types of params and results */
    uint8_t types[1];
} WASMType;

typedef struct  {
    uint16_t param_count;
    uint16_t result_count;
    uint16_t param_cell_num;
    uint16_t ret_cell_num;
    /* types of params and results */
    uint8_t types[];
} WASMType2;

typedef struct  {
    uint16_t param_count;
    uint16_t result_count;
    uint16_t param_cell_num;
    uint16_t ret_cell_num;
    /* types of params and results */
    uint8_t types[0];
} WASMType3;

int main() {
    std::cout << sizeof(WASMType) << std::endl;
    std::cout << sizeof(WASMType2) << std::endl;
    std::cout << sizeof(WASMType3) << std::endl;
    return 0;
}