From 15079ee79f85e63a2f578b9260871aefc9ffe66b Mon Sep 17 00:00:00 2001
From: UnknownShadow200 <unknownshadow200@gmail.com>
Date: Fri, 2 Aug 2019 19:37:03 +1000
Subject: [PATCH] Actually implement String_UNSAFE_SubstringAt as a function
 instead of a macro on top of String_UNSAFE_Substring

This saves around 1ms when loading 431 fonts on my PC
---
 src/Chat.c   |  2 +-
 src/String.c | 10 ++++++++++
 src/String.h |  3 ++-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/Chat.c b/src/Chat.c
index 9dbd919a4..c8ace367c 100644
--- a/src/Chat.c
+++ b/src/Chat.c
@@ -303,7 +303,7 @@ static void Commands_Execute(const String* input) {
 		offset = 1;
 	}
 
-	text = String_UNSAFE_Substring(&text, offset, text.length - offset);
+	text = String_UNSAFE_SubstringAt(&text, offset);
 	/* Check for only / or /client */
 	if (!text.length) { Commands_PrintDefault(); return; }
 
diff --git a/src/String.c b/src/String.c
index e2cc1deba..3ff91678e 100644
--- a/src/String.c
+++ b/src/String.c
@@ -61,6 +61,16 @@ String String_UNSAFE_Substring(STRING_REF const String* str, int offset, int len
 	return String_Init(str->buffer + offset, length, length);
 }
 
+String String_UNSAFE_SubstringAt(STRING_REF const String* str, int offset) {
+	String sub;
+	if (offset < 0 || offset > str->length) Logger_Abort("Sub offset out of range");
+
+	sub.buffer   = str->buffer + offset;
+	sub.length   = str->length - offset;
+	sub.capacity = str->length - offset; /* str->length to match String_UNSAFE_Substring */
+	return sub;
+}
+
 int String_UNSAFE_Split(STRING_REF const String* str, char c, String* subs, int maxSubs) {
 	int beg = 0, end, count, i;
 
diff --git a/src/String.h b/src/String.h
index 93090586c..1c0973ac5 100644
--- a/src/String.h
+++ b/src/String.h
@@ -67,7 +67,8 @@ CC_API void String_CopyToRaw(char* dst, int capacity, const String* src);
 /* UNSAFE: Returns a substring of the given string. (sub.buffer is within str.buffer + str.length) */
 CC_API String String_UNSAFE_Substring(STRING_REF const String* str, int offset, int length);
 /* UNSAFE: Returns a substring of the given string. (sub.buffer is within str.buffer + str.length) */
-#define String_UNSAFE_SubstringAt(str, offset) (String_UNSAFE_Substring(str, offset, (str)->length - (offset)))
+/* The substring returned is { str.buffer + offset, str.length - offset } */
+CC_API String String_UNSAFE_SubstringAt(STRING_REF const String* str, int offset);
 /* UNSAFE: Splits a string of the form [str1][c][str2][c][str3].. into substrings. */
 /* e.g., "abc:id:xyz" becomes "abc","id","xyz" */
 CC_API int String_UNSAFE_Split(STRING_REF const String* str, char c, String* subs, int maxSubs);