int DFS(a, b,c,d)
{
first=a+b;
second=c+d;
return(first,second);
}
solution, cost_limit = DFS(a, b,c,d);
can I do something like this ? and how?
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It's very unclear what you're asking here. I would suggest you explain what you mean by assign, and what you mean by a variable.Samuel Harmer– Samuel Harmer2012-01-12 10:55:33 +00:00Commented Jan 12, 2012 at 10:55
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5 Answers
In C++11 you can use the tuple types and tie for that.
#include <tuple>
std::tuple<int, int> DFS (int a, int b, int c, int d)
{
return std::make_tuple(a + b, c + d);
}
...
int solution, cost_limit;
std::tie(solution, cost_limit) = DFS(a, b, c, d);
5 Comments
Luc Touraille
If C++11 is not an option, the Boost Tuple library provides these features.
Antonio Pérez
If C++11 is not an option, you still can use C++03's
std::pair<int, int>
Steve Jessop
@Antionio: but there's no
tie in C++03, so it comes out looking pretty ugly: std::pair<int, int> result = DFS(a,b,c,d); solution = result.first; cost_limit = result.second;.
filmor
You could use TR1, I think that one also features the tuple library (with
tie)
madhur4127
in C++17, use structured declarations with pair
With C++17, you can unpack a pair or a tuple
auto[i, j] = pair<int, int>{1, 2};
cout << i << j << endl; //prints 12
auto[l, m, n] = tuple<int, int, int>{1, 2, 3};
cout << l << m << n << endl; //prints 123
2 Comments
Ciro Santilli OurBigBook.com
And you don't need the
<int, int> anymore BTW: stackoverflow.com/questions/9270563/…
Audrius Meškauskas
This is bundled with declaration. The question is how to assign to existing variable.
You can do this two ways:
Create a struct with two values and return it:
struct result { int first; int second; }; struct result DFS(a, b, c, d) { // code }Have out parameters:
void DFS(a, b, c, d, int& first, int& second) { // assigning first and second will be visible outside }call with:
DFS(a, b, c, d, first, second);
One thing you should be know is that if a,b,c,d are not base types, but instances of a class you defined, let's say Foo, and you overload the = operator of the class, you must ensure the fact that the operator will return a reference to the object which is assigned, or else you will not be able to chain assignments ( solution = cost_limit = DFS(..) will only assign to cost_limit). The = operator should look like this:
Foo& Foo::operator =(const Foo& other)
{
//do stuff
return other;
}
Comments
If C++11 is not possible, it's possible to use references.
By passing a reference to variables in parameters.
int DFS(int a, int b, int c, int d, int &cost_limit)
{
cost_limit = c + d;
return a + b;
}
int solution, cost_limit;
solution = DFS(a, b, c, d, cost_limit);
