Added RHASH_SET_IFNONE/rb_hash_set_ifnone

These are basically the C equivalents of Hash#default=.

spec/ruby/optional/capi/ext/hash_spec.c

@@ -105,6 +105,12 @@ VALUE hash_spec_rb_hash_size(VALUE self, VALUE hash) {
 }
 #endif
 
+#ifdef HAVE_RB_HASH_SET_IFNONE
+VALUE hash_spec_rb_hash_set_ifnone(VALUE self, VALUE hash, VALUE def) {
+  return rb_hash_set_ifnone(hash, def);
+}
+#endif
+
 void Init_hash_spec() {
   VALUE cls;
   cls = rb_define_class("CApiHashSpecs", rb_cObject);
@@ -152,6 +158,10 @@ void Init_hash_spec() {
 #ifdef HAVE_RB_HASH_SIZE
   rb_define_method(cls, "rb_hash_size", hash_spec_rb_hash_size, 1);
 #endif
+
+#ifdef HAVE_RB_HASH_SET_IFNONE
+  rb_define_method(cls, "rb_hash_set_ifnone", hash_spec_rb_hash_set_ifnone, 2);
+#endif
 }
 
 #ifdef __cplusplus

spec/ruby/optional/capi/ext/rubyspec.h

@@ -327,6 +327,7 @@
 #define HAVE_RB_HASH_LOOKUP2               1
 #define HAVE_RB_HASH_NEW                   1
 #define HAVE_RB_HASH_SIZE                  1
+#define HAVE_RB_HASH_SET_IFNONE            1
 
 /* Integer */
 #ifdef RUBY_VERSION_IS_2_1

spec/ruby/optional/capi/hash_spec.rb

@@ -168,4 +168,14 @@
       end
     end
   end
+
+  describe "rb_hash_set_ifnone" do
+    it "sets the default value of non existing keys" do
+      hash = {}
+
+      @s.rb_hash_set_ifnone(hash, 10)
+
+      hash[:chunky].should == 10
+    end
+  end
 end

vm/capi/hash.cpp

@@ -80,4 +80,10 @@ extern "C" {
       }
     }
   }
+
+  VALUE rb_hash_set_ifnone(VALUE hash, VALUE def) {
+    capi_fast_call(hash, rb_intern("default="), 1, def);
+
+    return hash;
+  }
 }

vm/include/capi/ruby/ruby.h

@@ -421,6 +421,8 @@ struct RFloat {
 #define RHASH(obj)      ({ C_API_RHASH_is_not_supported_in_Rubinius })
 #define RHASH_TBL(obj)  ({ C_API_RHASH_TBL_is_not_supported_in_Rubinius })
 
+#define RHASH_SET_IFNONE(hash, def) rb_hash_set_ifnone(hash, def)
+
 typedef struct rb_io_t {
   VALUE handle;
   int fd;
@@ -1462,6 +1464,8 @@ struct RTypedData {
                        int (*func)(ANYARGS),
                        VALUE farg);
 
+  VALUE rb_hash_set_ifnone(VALUE hash, VALUE def);
+
   void    rb_eof_error();
 
   VALUE rb_io_addstr(VALUE, VALUE);