Add function string::insert.

(more overloads for it can be added later).

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@5788 dfc29bdd-3216-0410-991c-e03cc46cb475

changes.txt

@@ -1,5 +1,6 @@
 --------------------------
 Changes in 1.9 (not yet released)
+- Add function string::insert.
 - EditBox now still allows overwriting characters when the text-length is at max.
 - Bugfix: CMatrix4::transformPlane was calculating the wrong plane-normal before. 
 - SViewFrustum::recalculateBoundingBox no longer includes camera position in the bounding-box. Only using frustum corners now. Thx @DevSH for bugreport & patch.

include/irrString.h

@@ -730,6 +730,32 @@ public:
 		return *this;
 	}
 
+	//! Insert a certain amount of characters into the string before the given index
+	//\param pos Insert the characters before this index
+	//\param s String to insert. Must be at least of size n
+	//\param n Number of characters from string s to use.
+	string<T,TAlloc>& insert(u32 pos, const char* s, u32 n)
+	{
+		if ( pos < used )
+		{
+			reserve(used+n);
+
+			// move stuff behind insert point
+			const u32 end = used+n-1;
+			for (u32 i=0; i<used-pos; ++i)
+			{
+				array[end-i] = array[end-(i+n)];
+			}
+			used += n;
+
+			for (u32 i=0; i<n; ++i)
+			{
+				array[pos+i] = s[i];
+			}
+		}
+
+		return *this;
+	}
 
 	//! Reserves some memory.
 	/** \param count: Amount of characters to reserve. */

tests/irrString.cpp

@@ -180,6 +180,29 @@ bool testAppendStringc()
 	return true;
 }
 
+bool testInsert()
+{
+	core::stringc str;
+
+	str.insert(0, "something", 4);
+	if (str != "some")
+		return false;
+
+	str.insert(4, "thing", 5);
+	if (str != "something")
+		return false;
+
+	str.insert(0, "is ", 3);
+	if (str != "is something")
+		return false;
+
+	str.insert(3, "there ", 6);
+	if (str != "is there something")
+		return false;
+
+	return true;
+}
+
 bool testLowerUpper()
 {
 	irr::core::array <irr::core::stringc> stringsOrig, targetLower, targetUpper;
@@ -356,6 +379,8 @@ bool testIrrString(void)
 	}
 	allExpected &= testAppendStringc();
 
+	allExpected &= testInsert();
+
 	logTestString("Test io::path\n");
 	{
 		// Only test that this type exists, it's one from above

tests/tests-last-passed-at.txt

@@ -1,4 +1,4 @@
 Tests finished. 1 test of 1 passed.
 Compiled as DEBUG
-Test suite pass at GMT Fri Feb 22 17:53:28 2019
+Test suite pass at GMT Fri Mar 15 13:00:55 2019