Как массив char[4] перевести в unsigned int?

        unsigned int B=0;
        long Ex = 256 * 256 * 256;
        for (int i=0; i<4; i++)
        {
                B8 += t[i] * Ex;
                Ex /= 256;
         }

char ch[4] = {'a', 'b', 'c', 'd'};
int i = *(int *)ch;

 char t[4] ={0x04,0x03,0x02,0x01};
 int ex=0;
 
 for(int i=0;i<4;i++)
 ex+=(int)t[i]<<(i<<3);

union
{
char t[4];
int i;
} number = {'a','b','c','d'};

unsigned int uintof4b(char buffer[4])
{
    unsigned int x = 0;
    for (int i = 0; i < 4; i++)
    {
        x += (unsigned char)buffer[3 - i] << (i << 3);
    }
    return x;
}

unsigned int uintof4b(char buffer[4])
{
    unsigned int x = 0;
    for (int i = 0; i < 4; i++)
    {
        x |= static_cast<unsigned int>(buffer[3 - i]) << (i * 8);
    }
    return x;
}

(unsigned char)buffer[3 - i] << (i << 3)

memcpy(&x, buffer, sizeof(int));

static_cast<unsigned char>(buffer[3 - i])

(buffer[3 - i] & 0x000000FF)

unsigned char *uns_buffer = reinterpret_cast<unsigned char *>buffer;

        unsigned char buf[4];
        unsigned int x = 0;
        for (int i = 0; i < 4; i++)
            buf[i] = ifs.get();
        for (int i = 0; i < 4; i++)
            x += buf[3 - i] << (i << 3);

        unsigned int x = 0;
        for (int i = 0; i < 4; i++)
            x += static_cast<unsigned int>(ifs.get()) << ((3 - i) << 3);

unsigned int x = 0;     
for (__int8 i = 3; i >= 0; i--)
    x += (unsigned int)(ifs.get()) << (i << 3);

unsigned int x = 0;
for (__int8 i = 3; i >= 0; i--)
    x += (ifs.get()) << (i << 3);