From 44ef56941e945eaf8f06d3cacc5ed1b82dd56309 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kjist=C3=B3f?= <mrtoth@strongds.hu>
Date: Sun, 23 Oct 2016 15:28:28 +0200
Subject: [PATCH] made an index_of() method for StringValue, which calculates
 the index of a char

---
 StringValue.cpp | 11 ++++++++++-
 StringValue.h   |  1 +
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/StringValue.cpp b/StringValue.cpp
index 90426ad..cee8e78 100644
--- a/StringValue.cpp
+++ b/StringValue.cpp
@@ -37,4 +37,13 @@ StringValue::operator const char*() const
 { return _data; }
 
 size_t StringValue::size() const
-{ return _size - 1; }
\ No newline at end of file
+{ return _size - 1; }
+
+size_t StringValue::index_of(char* c) const
+{
+    size_t index = c - _data;   // this is totally safe pointer-arithmetic
+    if (index <= this->size())  // if it is within our data
+        return index;
+    else
+        throw std::invalid_argument("char* not within held data!");
+}
\ No newline at end of file
diff --git a/StringValue.h b/StringValue.h
index 1a65bba..5cebb8a 100644
--- a/StringValue.h
+++ b/StringValue.h
@@ -28,4 +28,5 @@ public:
     char& operator[](size_t index);
     operator const char*() const;
     size_t size() const;
+    size_t index_of(char* c) const;
 };
\ No newline at end of file