Hi,
There's been a discussion here on a similar topic that I'd like to
push a step further.
Suppose I get a class S having constructors:
S(int n) - allocates n bytes of memory
S() - allocates nothing
and a copy constructor,cop y assigment op. and so on.
I intend to declare a table of structures that contain (among other
things)objects of S with some memory allocated. When I simple-minded
code something like this:
struct {
S field1(20); //error here
...
} x[100];
then my compiler insists to use default constructor which doesn't
allocate anything. And all my attempts to apply some object oriented
programming like:
class X {
S field1;
...
X(int n): field1(n) {}
};
X x[100];
for(i...)
{ X xxx(20); //to get space for xxx
x[i] = xxx; //hope the memory chunk will be assigned to x[i]
}
fall short because the operator= doesn't allocate memory, and flags an
error. In other words, it can't copy an object to an "empty" one).
Well, I could use vector<> or another container (or even overload
operators of S yet I'd prefer not doing so) but this thought's
torturing me in this New Year Eve: how to use a built-in tables to
keep objects? Books (ex.Lippmann's one) claim that's possible but give
no hints.
Happy New Year to those who will reply to my post and those who won't.
X.
There's been a discussion here on a similar topic that I'd like to
push a step further.
Suppose I get a class S having constructors:
S(int n) - allocates n bytes of memory
S() - allocates nothing
and a copy constructor,cop y assigment op. and so on.
I intend to declare a table of structures that contain (among other
things)objects of S with some memory allocated. When I simple-minded
code something like this:
struct {
S field1(20); //error here
...
} x[100];
then my compiler insists to use default constructor which doesn't
allocate anything. And all my attempts to apply some object oriented
programming like:
class X {
S field1;
...
X(int n): field1(n) {}
};
X x[100];
for(i...)
{ X xxx(20); //to get space for xxx
x[i] = xxx; //hope the memory chunk will be assigned to x[i]
}
fall short because the operator= doesn't allocate memory, and flags an
error. In other words, it can't copy an object to an "empty" one).
Well, I could use vector<> or another container (or even overload
operators of S yet I'd prefer not doing so) but this thought's
torturing me in this New Year Eve: how to use a built-in tables to
keep objects? Books (ex.Lippmann's one) claim that's possible but give
no hints.
Happy New Year to those who will reply to my post and those who won't.
X.
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