Use of typedef for pointer

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If I’ve already set a pointer to my structure why can’t I make the allocation of it.

#include <stdio.h>
#include <stdlib.h>
struct ponto
{
   int a, b;
};

typedef struct ponto *Ponteiro; // define um ponteiro para estrutura ponto 
typedef struct ponto estrutura; // aqui chamo a estrutura ponto de estrutura

int main(int argc, char** argv)
{ 
    Ponteiro  = malloc(sizeof(estrutura)); 

    return 0;
}
c pointer variable-declaration typedef

1 answer

6


Thus?

#include <stdio.h>
#include <stdlib.h>

struct ponto {
   int a, b;
};

typedef struct ponto * Ponteiro;
typedef struct ponto estrutura;

int main() { 
    Ponteiro p = malloc(sizeof(estrutura));
    printf("%p", (void *)p);
}

Missing a variable, you cannot declare a variable without naming it.

It would look even better this way:

#include <stdio.h>
#include <stdlib.h>

typedef struct ponto {
   int a, b;
} Estrutura;

typedef Estrutura* Ponteiro;

int main() { 
    Ponteiro p = malloc(sizeof(Estrutura));
    printf("%p", (void *)p);
}

Behold working in the ideone. And in the repl it.. Also put on the Github for future reference.

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