Can I assign and return without a utility routine?
Is there a way to "assign and return" without creating a utility routine? Here's my code:
static int& do_work_(const int* p, int& result)
{
result = (*p) * 10;
return result;
}
template<typename T>
T& assign(const T* p, T& result)
{
result = *p;
return result;
}
int& do_work(const int* p, bool cond, int& result)
{
return cond ? do_work_(p, result) : assign(p, result);
}
Can I implement do_work()
without the assign()
utility?
The reason for the do_work()
signature is that it's a nice convenience:
const int value=1;
int i, j;
if (do_work(&value, true, i) == do_work(&value, false, j)) {}
If you want to return the result of an assignment operation you can (in most cases) do so without a 'utility' function like your assign
, because the assignment expression itself has a value; from cppreference (bolding mine):
The direct assignment operator expects a modifiable lvalue as its left operand and an rvalue expression or a braced-init-list (since C++11) as its right operand, and returns an lvalue identifying the left operand after modification.
Or, from this Draft C++17 Standard:
8.5.18 Assignment and compound assignment operators [expr.ass]
1 The assignment operator (=) and the compound assignment operators all group right-to-left. All require a modifiable lvalue as their left operand; their result is an lvalue referring to the left operand. …
Thus, as suggested in the comments, you can simply have the following:
int& do_work(const int* p, bool cond, int& result)
{
return cond ? do_work_(p, result) : (result = *p);
}