Add compiler settings like C standard and warning level.

CMakeLists.txt

@@ -1,6 +1,8 @@
 cmake_minimum_required(VERSION 2.7)
 project(libds)
 
+set_property(GLOBAL PROPERTY C_STANDARD 90)
+ADD_COMPILE_OPTIONS(-pedantic -Wall)
 include_directories(include)
 
 add_library(ds src/libds.c src/vec.c src/ht.c)

src/ht.c

@@ -126,4 +126,4 @@ int ht_foreach(ht* ht, void* data, compare_func compare, foreach_func foreach, .
         }
     }
     return return_code;
-}
+}