Can I get a C++ Compiler to instantiate objects at compile time
Posted
by
gam3
on Programmers
See other posts from Programmers
or by gam3
Published on 2012-09-15T22:10:40Z
Indexed on
2012/09/16
3:51 UTC
Read the original article
Hit count: 270
I am writing some code that has a very large number of reasonably simple objects and I would like them the be created at compile time. I would think that a compiler would be able to do this, but I have not been able to figure out how.
In C I could do the the following:
#include <stdio.h>
typedef struct data_s {
int a;
int b;
char *c;
} info;
info list[] = {
1, 2, "a",
3, 4, "b",
};
main()
{
int i;
for (i = 0; i < sizeof(list)/sizeof(*list); i++) {
printf("%d %s\n", i, list[i].c);
}
}
Using #C++* each object has it constructor called rather than just being layed out in memory.
#include <iostream>
using std::cout;
using std::endl;
class Info {
const int a;
const int b;
const char *c;
public:
Info(const int, const int, const char *);
const int get_a() { return a; };
const int get_b() { return b; };
const char *get_c() const { return c; };
};
Info::Info(const int a, const int b, const char *c) : a(a), b(b), c(c) {};
Info list[] = {
Info(1, 2, "a"),
Info(3, 4, "b"),
};
main()
{
for (int i = 0; i < sizeof(list)/sizeof(*list); i++) {
cout << i << " " << list[i].get_c() << endl;
}
}
I just don't see what information is not available for the compiler to completely instantiate these objects at compile time, so I assume I am missing something.
© Programmers or respective owner