方法调用后字节大小不正确

我制作了一个最小的工作示例,我有一大段代码.

问题是,sizeof打印第一次调用16,这是正确的大小,而第二次调用只打印8.奇怪的是,它总是打印8,独立于结构的大小,是否只有一个值或10个值.

struct test_struct
{
    int32_t val1;
    int32_t val2;
    int32_t val3;
    int32_t val4;
};

unsigned char * StructToChar(test_struct structy)
{
    unsigned char returnval[sizeof(structy)];
    memcpy(returnval, &structy, sizeof(structy));
    return returnval;
}

int main()
{
    test_struct sendstruct = {};
    unsigned char *test_array = StructToChar(sendstruct);

    unsigned char returnval[sizeof(sendstruct)];
    memcpy(returnval, &sendstruct, sizeof(sendstruct));

    printf("%d\n", sizeof(returnval));
    printf("%d\n", sizeof(test_array));
    return 0;
}

Jarod42.. 5

sizeof(test_array)是sizeof(unsigned char *)如此大小的指针.

sizeof(test_array)是sizeof(unsigned char *)如此大小的指针.