Wint-in-bool-context what causes this warning?

I have searched on google but I have no luck to find the cause of this warning Wint-in-bool-context

The compiler gives me the following warning:

 warning: enum constant in boolean context [-Wint-in-bool-context]
              : (excess_bits ? (((uint64_t)VAL) << (excess_bits)) >> (excess_bits)
                   ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                            : (uint64_t)VAL));

This is the code line related with this warning:

std::vector<ap_int<32>> B(n*m);
for(int i = 0;i < m;i++){ 
...
B.data()[i * n + j] =  0x00000001;
...
} 

-Wint-in-bool-context is exactly as it sounds. You're using an integer value and allowing it to behave implicitly like a bool (e.g. any nonzero value is true).

In your (limited) snippet, it's likely because excess_bits is an integral value and not bool. To silence such a warning, explicitly cast instead, or perform a check that evaluates to a boolean expression -- such as:

              : (static_cast<bool>(excess_bits) ? (((uint64_t)VAL) << (excess_bits)) >> (excess_bits)
//              ^~~~~~~~~~~~~~~~~~~           ~ Tell compiler we want a bool

Or

              : ((excess_bits != 0) ? (((uint64_t)VAL) << (excess_bits)) >> (excess_bits)

The second snippet you provide is less clear because we don't have the error, exact offending line, or the definition of ap_int<32>. If I had to guess, the assignment of

B.data()[i * n + j] =  0x00000001;

Should probably be assigning true instead of a numeric value; but this is just a guess, since no context has been given here.