Added fast path for dchars in std.utf.byUTF

JackStouffer · JackStouffer · commit 6c5f8a4149a0 · 2016-07-28T16:07:29.000-04:00
diff --git a/std/utf.d b/std/utf.d
@@ -3609,8 +3609,16 @@ template byUTF(C) if (isSomeChar!C)
                         }
                         else
                         {
-                            fill = cast(ushort)encode!(UseReplacementDchar.yes)(
-                                buf, decodeFront!(UseReplacementDchar.yes)(r));
+                            static if (is(RC == dchar))
+                            {
+                                fill = cast(ushort) encode!(UseReplacementDchar.yes)(buf, c);
+                                r.popFront;
+                            }
+                            else
+                            {
+                                fill = cast(ushort) encode!(UseReplacementDchar.yes)(
+                                    buf, decodeFront!(UseReplacementDchar.yes)(r));
+                            }
                         }
                     }
                     return buf[pos];

Original file line number	Diff line number	Diff line change
`@@ -3609,8 +3609,16 @@ template byUTF(C) if (isSomeChar!C)`
`3609`	`3609`	`}`
`3610`	`3610`	`else`
`3611`	`3611`	`{`
`3612`		`- fill = cast(ushort)encode!(UseReplacementDchar.yes)(`
`3613`		`- buf, decodeFront!(UseReplacementDchar.yes)(r));`
	`3612`	`+ static if (is(RC == dchar))`
	`3613`	`+ {`
	`3614`	`+ fill = cast(ushort) encode!(UseReplacementDchar.yes)(buf, c);`
	`3615`	`+ r.popFront;`
	`3616`	`+ }`
	`3617`	`+ else`
	`3618`	`+ {`
	`3619`	`+ fill = cast(ushort) encode!(UseReplacementDchar.yes)(`
	`3620`	`+ buf, decodeFront!(UseReplacementDchar.yes)(r));`
	`3621`	`+ }`
`3614`	`3622`	`}`
`3615`	`3623`	`}`
`3616`	`3624`	`return buf[pos];`