Implement rb_str_catf

Author: bjfish

CHANGELOG.md

@@ -21,6 +21,7 @@ Compatibility:
 * Implement `rb_fiber_*` functions (#2402).
 * Implement `rb_str_vcatf`.
 * Add support for tracing allocations from C functions (#2403, @chrisseaton).
+* Implement `rb_str_catf`.
 
 Performance:
 

lib/cext/ABI_version.txt

@@ -1 +1 @@
-8
+9

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

@@ -513,6 +513,10 @@ static VALUE string_spec_rb_str_vcatf(VALUE self, VALUE mesg) {
   return call_rb_str_vcatf(mesg, "fmt %d %d number", 42, 7);
 }
 
+static VALUE string_spec_rb_str_catf(VALUE self, VALUE mesg) {
+  return rb_str_catf(mesg, "fmt %d %d number", 41, 6);
+}
+
 void Init_string_spec(void) {
   VALUE cls = rb_define_class("CApiStringSpecs", rb_cObject);
   rb_define_method(cls, "rb_cstr2inum", string_spec_rb_cstr2inum, 2);
@@ -603,6 +607,7 @@ void Init_string_spec(void) {
   rb_define_method(cls, "rb_utf8_str_new", string_spec_rb_utf8_str_new, 0);
   rb_define_method(cls, "rb_utf8_str_new_cstr", string_spec_rb_utf8_str_new_cstr, 0);
   rb_define_method(cls, "rb_str_vcatf", string_spec_rb_str_vcatf, 1);
+  rb_define_method(cls, "rb_str_catf", string_spec_rb_str_catf, 1);
 }
 
 #ifdef __cplusplus

spec/ruby/optional/capi/string_spec.rb

@@ -1152,4 +1152,14 @@ def inspect
       str.should == "test fmt 42 7 number"
     end
   end
+
+  describe "rb_str_catf" do
+    it "appends the message to the string" do
+      @s.rb_str_catf("").should == "fmt 41 6 number"
+
+      str = "test "
+      @s.rb_str_catf(str)
+      str.should == "test fmt 41 6 number"
+    end
+  end
 end

src/main/c/cext/printf.c

@@ -146,3 +146,11 @@ VALUE rb_str_vcatf(VALUE str, const char *fmt, va_list args) {
   rb_str_concat(str, result);
   return str;
 }
+
+VALUE rb_str_catf(VALUE str, const char *format, ...) {
+  va_list ap;
+  va_start(ap, format);
+  str = rb_str_vcatf(str, format, ap);
+  va_end(ap);
+  return str;
+}