QString hex translation errors

[Bryan Kelly]

Windows 11, Qt Creator 12.0.2
I was doing some hex to binary translations and came across some errors. This is the code I added while verifying how things work. All is fine for 8 and 16 bits, but there are problems for 32 and 64 bits.
I removed the looping code used for my practics, index variable i is set to zero for the below results.

   union union_int_256
    {
        uint64_t int_64[  4 ];
        uint32_t int_32[  8 ];
        uint16_t int_16[ 16 ];
        uint8_t  int_08[ 32 ];  // 64 hex characters
};
…
    QString s08;
    QString s16;
    QString s32;
    QString s64;

    bool    b08;
    bool    b16;
    bool    b32;
    bool    b64;
    
    uint8_t  x08, z08;
    uint16_t x16, z16;
    uint32_t x32, z32;
    uint64_t x64, z64;

        x08 = binary->int_08[ i ];      // input: 0XE3 , 227
        s08.setNum( x08, 16 );          // s08 =  e3
        z08 = s08.toInt( &b08, 16 );    // z08 =  227,  b08 =  true

        x16 = binary->int_16[ i ];      // input: 0XCDE3, 5207
        s16.setNum( x16, 16 );          // s16 =  cde3
        z16 = s16.toInt( &b16, 16 );    // z16 =  5207,  b16 =  true

        x32 = binary->int_32[ i ];      // input: 89ABCDE3, 2309737955
        s32.setNum( x32, 16 );          // s32 =  89abcde3
        z32 = s32.toInt( &b32, 16 );    // z32 =  0,  b32 =  false

        x64 = binary->int_64[ i ];      // input: E2  0123456789ABCDE3, 81985529216486883
        s64.setNum( x64, 16 );          // s64 =  123456789abcde3
        z64 = s64.toInt( &b64, 16 );    // z64 =  0,  b64 =  false

and the variable part of the debugger is captured below

Any thoughts?

[Christian Ehrlicher]

@Bryan-Kelly said in QString hex translation errors:

Any thoughts

Since you don't tell us what you think is wrong nor provide some compileable code with test data - no.

I would guess you want to tell us that toInt() can not convert it back? If so - toInt() converts to a int32 according to the documentation.

[Bryan Kelly]

Hmmm, I though the results were a bit obvious. The status returned for 8 and 16 bits were true, and false for 32 and 64 bits. The hex to int value for 32 bit translation was zero, incorrect. Both the translations for 64 bit were incorrect.
I did not recognize anything in the documentation restricting the translate operation of 8 and 16 bits.

My search results did not return the same page that yours did, and were a bit less descriptiive, but still, did not indicate the 8 and 16 bit limitations.

[Christian Ehrlicher]

So my I guess is correct. Use the correct toFoo() functions if you want everything greater than an int.

[JonB]

@Christian-Ehrlicher
I have not tested OP's code and don't have Qt availability. While what you say may be the case for the uint64_t type, the OP claims it goes wrong for 32-bit (uint32_t ) case as well, which should be int?

[Christian Ehrlicher]

@JonB said in QString hex translation errors:

it goes wrong for 32-bit (uint32_t ) case as well, which should be int?

u = unsigned

[JonB]

@Bryan-Kelly said in QString hex translation errors:

    x32 = binary->int_32[ i ];      // input: 89ABCDE3, 2309737955
    s32.setNum( x32, 16 );          // s32 =  89abcde3
    z32 = s32.toInt( &b32, 16 );    // z32 =  0,  b32 =  false

In the light of what @Christian-Ehrlicher has just said, can you try this with 0-7 instead of 8-F as the leading hex digit? :) Do ir with e.g. s32 = 79abcde3, what's the result? And, try the original but use uint QString::toUInt(bool *ok = nullptr, int base = 10) const. The variants for 64-bit use Long/ULong.