Add #include preprocessing to filamat and matc (#1541)

* Add #include preprocessing to filamat and matc

* Update RELEASE_NOTES

* Fix RELEASE_NOTES

* Use final instead of virtual / override

* Clarify comments

* Use pure virtual for includer functions

* Use a callback instead of an interface

* Rename Includer.h to IncludeCallback.h

* Update comment

libs/utils/src/CString.cpp

@@ -18,6 +18,7 @@
 
 #include <utils/compiler.h>
 
+#include <algorithm>
 #include <memory>
 
 namespace utils {
@@ -61,4 +62,39 @@ CString& CString::operator=(const CString& rhs) {
     return *this;
 }
 
+CString& CString::replace(size_type pos, size_type len, const CString& str) noexcept {
+    assert(pos <= size());
+
+    len = std::min(len, size() - pos);
+
+    // The new size of the string, after the replacement.
+    const size_type newSize = size() - len + str.size();
+
+    // Allocate enough memory to hold the new string.
+    Data* p = (Data*) malloc(sizeof(Data) + newSize + 1);
+    assert(p);
+    p->length = newSize;
+    value_type* newStr = (value_type*) (p + 1);
+
+    const value_type* beginning = mCStr;
+    const value_type* replacementStart = mCStr + pos;
+    const value_type* replacementEnd = replacementStart + len;
+    const value_type* end = beginning + size();
+
+    value_type* ptr = newStr;
+    ptr = std::uninitialized_copy(beginning, replacementStart, ptr);
+    ptr = std::uninitialized_copy_n(str.c_str_safe(), str.length(), ptr);
+    ptr = std::uninitialized_copy(replacementEnd, end, ptr);
+
+    // null-terminator
+    *ptr = 0;
+
+    std::swap(mCStr, newStr);
+    if (newStr) {
+        free((Data*) newStr - 1);
+    }
+
+    return *this;
+}
+
 } // namespace utils