Thread: Objects contractor & compiler options

I have two qustions :

1. I am able to initialize a new object with some other object.
Is this part of c++ ? How is it done. I dont have a constractor function that recives an ojbect type.

2. Using gcc (redhat linux 8.0) How do I use compiler options
other than c.

This is a sample code :

Code:

class test
{
public:
float   f1;
char    str[100];
int     i;
float   f2;
void show(void)
{
   printf("f1 = %2.2f str = %s i = %d f2 = %2.2f\n",
                 f1, str, i, f2);
}
};


int   main(void)
{
test  t1;


t1.f1 = 3.2;
strcpy(t1.str, "my test");
t1.i = 777;
t1.f2 = -9.2;

t1.show();
test  t2(t1);   // Well I dont have a constractor of the type
                      // test::test(test t) 
                     // Is this something done by my compiler ?
                     // Is this part of c++ standard ?
                     // Can I turn this off with acompiler option ?

t2.show();     // the same values as t1 !!!!



return(0);

}

The Makefile




Makefile
myexec: main.cpp
g++ -Wall -ggdb -Wno-parentheses −fno−elide−constructors -o $@ $^

Why do I get the error :

g++ -Wall -ggdb -Wno-parentheses −fno−elide−constructors -o myexec main.cpp

g++: −fno−elide−constructors: No such file or directory

make: *** [myexec] Error 1



Thanks all advance.

you need a copy constructor.
test(const test&);

> g++: −fno−elide−constructors: No such file or directory
Well the 'minus' you use here is a lot different from the minus you use elsewhere on the command line.
Try editing the makefile and using the correct characters.

Code:

$ od -t x1z
g++: −fno−elide−constructors: No such file or directory
0000000 67 2b 2b 3a 20 e2 88 92 66 6e 6f e2 88 92 65 6c  >g++: ...fno...el<
0000020 69 64 65 e2 88 92 63 6f 6e 73 74 72 75 63 74 6f  >ide...constructo<
0000040 72 73 3a 20 4e 6f 20 73 75 63 68 20 66 69 6c 65  >rs: No such file<
0000060 20 6f 72 20 64 69 72 65 63 74 6f 72 79 0a        > or directory.<

e2 88 92 is not a normal -