Convert Binary String to Integer Without strtol function or Libraries

No error handling

#include <stdio.h>
#include <stdint.h>

uint16_t binary_to_uint(const char *str) {
    uint16_t ret_val = 0;
    while(*str){
        ret_val <<= 1;      //multiply by 2
        ret_val |= (*str == '1') ? 1 : 0 ;

        str++;
    }
    return ret_val;
}

int main() {
    char bin[20];
    scanf("%s", bin);

    printf("%u", binary_to_uint(bin));
    return 0;
}

Solving Approach