errors as i use the restrict qualifier
c, pointers, restrict-qualifier
Solution
Not all compilers are compliant with the C99 standard. For example Microsoft's compiler, does not support the C99 standard at all. If you are using MSVC on a x86 platform you will not have access to this critical optimization option.
When using GCC, remember to enable the C99 standard by adding -std=c99 to your compilation flags. In code that cannot be compiled with C99, use either `__restrict` or `__restrict__` to enable the keyword as a GCC extension.
From here.
Problem
When I compile the following program I get errors : ``` gcc tester.c -o tester tester.c: In function ‘main’: tester.c:7:17: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘ptr_X’ tester.c:7:17: error: ‘ptr_X’ undeclared (first use in this function) tester.c:7:17: note: each undeclared identifier is reported only once for each function it appears in tester.c:10:17: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘ptr_Y’ tester.c:10:17: error: ‘ptr_Y’ undeclared (first use in this function) ``` ``` #include <stdio.h> int main() { int x = 10; int y = 20; int *restrict ptr_X; ptr_X = &x; int *restrict ptr_Y; ptr_Y = &y; printf("%d\n",*ptr_X); printf("%d\n",*ptr_Y); } ``` Why am I getting these errors ?