I know the answer is 99.99% no, but I figured it was worth a try, you never know.
void SomeFunction(int a)
{
// Here some processing happens on a, for example:
a *= 50;
a %= 10;
if(example())
a = 0;
// From this point on I want to make "a" const; I don't want to allow
// any code past this comment to modify it in any way.
}
I can do something somewhat similar with const int b = a;
, but it's not really the same and it creates a lot of confusion. A C++0x-only solution is acceptable.
EDIT: another less abstracted example, the one that made me ask this question:
void OpenFile(string path)
{
boost::to_lower(path);
// I want path to be constant now
ifstream ...
}
EDIT: another concrete example: Recapture const-ness on variables in a parallel section.
One solution would be to factor all of the mutation code into a lambda expression. Do all of the mutation in the lambda expression and assign the result out to a const int
in the method scope. For example
void SomeFunction(const int p1) {
auto calcA = [&]() {
int a = p1;
a *= 50;
a %= 10;
if(example())
a = 0;
..
return a;
};
const int a = calcA();
...
}
or even
void SomeFunction(const int p1) {
const int a = [&]() {
int a = p1;
a *= 50;
a %= 10;
if(example())
a = 0;
..
return a;
}();
...
}