HP aC++/HP C A.06.28 Programmer's Guide Integrity servers (769150-001, March 2014)

For example, when your archive library is linked with an application, library objects in the link
may be different than those used when linking the library in a prior release.
Following are two examples of building an archive library; one built with
+inst_auto/+inst_close (the prior default), and the other built with the current (compile-time)
default:
Building an Archive Library with +inst_auto/+inst_close
Suppose for lib.inst_auto.a, the linker chooses foo2.o to resolve symbol x, and foo3.o
to resolve symbol stack <int>, symbols x, y, and stack <int> are each resolved with no
duplicates.
lib.inst_auto.a
-------------------------------------------------
| foo.o | foo2.o | foo3.o |
| | | stack<int> |
| x | x | y |
| y | | |
-------------------------------------------------
Building an Archive Library with Compile-time Instantiation
Suppose for lib.default.a, the linker chooses foo2.o to resolve symbol x, and foo.o to
resolve symbol stack <int>, symbols x, y, and stack <int> are each resolved, but now
there’s a duplicate definition of symbol x. This will cause a linker duplicate symbol error. This is
really a user error, but was not visible before.
lib.default.a
-------------------------------------------------
| foo.o | foo2.o | foo3.o |
| stack<int> | stack<int> | stack<int> |
| x | x | y |
| y | | |
-------------------------------------------------
NOTE: This example is not meant to account for all cases of changed behavior.
C++ Template Tutorial
You can create class templates and function templates. A template defines a group of classes or
functions. A template can have one or more types as parameters. When you use a template, you
provide the particular types or constant expressions as actual parameters thereby creating a
particular object or function.
Class Templates
A class template defines a family of classes. To declare a class template, you use the keyword
template followed by the template’s formal parameters. Class templates can take parameters
that are either types or expressions. You define a template class in terms of those parameters. For
example, the following is a class template for a simple stack class. The template has two parameters,
the type specifier T and the int parameter size. The keyword class in the < > brackets is
required to declare any template type parameters. The first parameter T is used for the stack element
type. The second parameter is used for the maximum size of the stack.
template<class T, int size>
class Stack
{
public:
Stack(){top=-1;}
void push(const T& item){thestack[++top]=item;}
T& pop(){return thestack[top--];}
private:
T thestack[size];
136 Using HP aC++ Templates