Warning C26498
The function 'function' is constexpr, mark variable 'variable' constexpr if compile-time evaluation is desired (con.5)
This rule helps to enforce Con.5 from the C++ Core Guidelines: use constexpr for values that can be computed at compile time.
Remarks
The warning is triggered by assigning the result of a constexpr function to any non-constexpr variable whose value doesn't change after the initial assignment.
Code analysis name: USE_CONSTEXPR_FOR_FUNCTIONCALL
Example
This sample code shows where C26498 may appear:
constexpr int getMyValue()
{
return 1;
}
void foo()
{
constexpr int val0 = getMyValue(); // no C26498
const int val1 = getMyValue(); // C26498, C26814
int val2 = getMyValue(); // C26498, value is never modified
int val3 = getMyValue(); // no C26498, val3 is assigned to below.
val3 = val3 * val2;
}
To fix the issues, mark val1 and val2 constexpr:
constexpr int getMyValue()
{
return 1;
}
void foo()
{
constexpr int val0 = getMyValue(); // OK
constexpr int val1 = getMyValue(); // OK
constexpr int val2 = getMyValue(); // OK
int val3 = getMyValue(); // OK
val3 = val3 * val2;
}