flaw in b2::bind::operator+ fixed (#485)

flaw in b2::bind::operator+ fixed

Author: paolopas

doc/src/history.adoc

@@ -3,6 +3,10 @@
 
 == Version 5.5.0
 
+* Fix jam/{CPP} bind definitions of 4 or more values in a single
+  declared argument not actually adding all the definitions.
+  -- _Paolo Pastori_
+
 == Version 5.4.2
 
 Fix detection of Visual Studio 2026 to account for non-native tools being

src/engine/bind.h

@@ -131,7 +131,7 @@ template <int C>
 arg_<C + 1> operator+(const arg_<C> & a, const param_ & b)
 {
 	arg_<C + 1> result;
-	for (std::size_t i = 0; i < C - 1; ++i) result.args[i] = a.args[i];
+	for (std::size_t i = 0; i < C; ++i) result.args[i] = a.args[i];
 	result.args[C] = b;
 	return result;
 }