segmentation fault - C++ deque throwing Segfaults -

i have code project doesn't seem working.

i trying make deque (of struct) static member of class. skeleton/basic code follows (i have retained datatypes - my_typedef_fn data type got typedef-ing function pointer) :

1.h file :

class {     struct bstruct {         char * b_name;         my_typedef_fn b_func;     }     static std::deque<bstruct> a_deque;     static void func(); } 

1.cpp file :

std::deque<a::bstruct> a::a_deque; void a::func(char * name, my_typedef_fn fn) {     a_deque.push_front((bstruct) {name, fn} ); // <<<< segfault ! }  

from understanding - .h file declares stuff (as usual) - first line in .cpp initializes static member a_deque - function func adds stuff deque using push_back

but segmentation error @ line push_front called (found using gdb).

also, when print a_deque.size() before push_front 4294967264 before segfault , when count number of elements in deque using loop :

int counter = 0 for( std::deque<bstruct> = a_deque.begin(); != a_deque.end(); it++, counter++ ); 

my counter shows 0 elements in

so, not understand why segfault nor why .size() large garbage number

-- edit 1 -- adding way functions called :

2.cpp

#include "1.h" void fn1() {      // code } a::func("abc", fn1); 

it complied commands :

g++ -c -w -fpermissive -o 1.o 1.cpp g++ -c -w -fpermissive -o 2.o 2.cpp g++ -o final 1.o 2.o 

it not possible call function in global scope, you're showing in 2.cpp. mentioned code old, maybe it's pre-standard thing, or extension.

anyway, you've shown function being called in 2.cpp, while static data member a_deque defined in 1.cpp. means you're falling prey static initialisation order fiasco. globals (such static data members, , apparently weird free-standing function call well) initialised/executed in order appear within 1 translation unit (= .cpp file), order across translation units unspecified.

which means it's possible a::func() access a_deque before constructor of a_deque has run, possibly lead segfault (as internal data members of deque have 0 or possibly random values).

to fix this, you'll have rid of situation somehow. 1 option move global code can access a_deque 1.cpp , place after definition of a_deque.

an alternative replace a_deque function-scope static variable, guaranteed initialised before first use:

1.h

class {     struct bstruct {         char * b_name;         my_typedef_fn b_func;     }     static std::deque<bstruct>& a_deque();     static void func(); } 

1.cpp

#include "1.h"  std::deque<a::bstruct>& a::a_deque() {   static std::deque<bstruct> d;   return d; }  void a::func(char * name, my_typedef_fn fn) {     a_deque().push_front((bstruct) {name, fn} ); // <<<< no more segfault }