stream - stringstream >> uint8_t in hex? c++ -

i confused output of following code:

uint8_t x = 0, y = 0x4a; std::stringstream ss; std::string = "4a";   ss << std::hex << a; ss >> x;  std::cout << (int)x << " "<< (int)y << std::endl; std::cout << x << " "<< y <<std::endl; std::cout << std::hex << (int)x <<  " " << (int)y << std::endl;  uint8_t z(x); std::cout << z; 

the output above is:

52 74

4 j

34 4a

4

and when change replace first line with:

uint16_t x = 0, y = 0x4a; 

the output turns into:

74 74

74 74

4a 4a

j

i think understand happens don't understand why happens or how can prevent it/work around it. understanding std::hex modifier somehow undermined because of type of x, maybe not true @ technical level writes first character reads.

background: input supposed string of hexadecimal digits, each pair representing byte( bitmap except in string). want able read each byte , store in uint8_t experimenting when came across problem. still can't determine what's best method of if think i'm doing inefficient or unnecessary appreciate know why. thank reading,

ss >> x 

is treating uint8_t x unsigned char. ascii value of '4' (decimal) 52. it's reading first char of string "4a" x if x character. when switch uint16_t, it's treating unsigned short integer type. same y.