How to store a structure in a map?

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Is it possible to store a structure in a map?
and, if yes, how?
e.g.:

C++

struct struct1
{
int a;
int b;
float c;
fload d;
};

key of the map should be c and the mapped value should contain entire structure.

Posted 17-Oct-12 1:12am

newbie@work

Updated 17-Oct-12 2:03am

CPallini

v2

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CPallini 17-Oct-12 8:02am

skydger gave you the solution. I would add that using float values as map keys is (unless you really know what are you doing) not a good idea. See
http://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/

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skydger · Answer 1 · 2012-10-17T01:51:00

Solution 1

Yes, it is possible, try this code

C++

typedef struct struct1{
    int a;
    int b;
    float c;
    float d;
} my_struct_t;
//...
my_struct_t st = { 1, 2, 3.0, 4,0 };
std::map< float, my_struct_t > my_struct_map;
std::pair< float, my_struct_t > p = std::make_pair( st.c, st );
my_struct_map.insert(p);

Posted 17-Oct-12 1:51am

skydger

Updated 17-Oct-12 1:52am

v2

Comments

CPallini 17-Oct-12 7:58am

My 5.
Note you don't need the typedef.

skydger 17-Oct-12 8:14am

Thanks for advice :)

CPallini 17-Oct-12 8:30am

You are welcome.

newbie@work 17-Oct-12 8:44am

Thank you guys. I was doing the same thing, one crazy error was that I was declaring the structure in the same locale scope. Because of which I couldnt store the object in the map. Stupid, Stupid me!