+ BOOST_EXPLICIT_TEMPLATE_TYPE(t)
+ BOOST_EXPLICIT_TEMPLATE_NON_TYPE(t, v)
+
+ BOOST_APPEND_EXPLICIT_TEMPLATE_TYPE(t)
+ BOOST_APPEND_EXPLICIT_TEMPLATE_NON_TYPE(t, v)
+ |
+ Some compilers silently "fold" different function template
+ instantiations if some of the template parameters don't appear
+ in the function parameter list. For instance:
+
+ #include <iostream>
+ #include <ostream>
+ #include <typeinfo>
+
+ template <int n>
+ void f() { std::cout << n << ' '; }
+
+ template <typename T>
+ void g() { std::cout << typeid(T).name() << ' '; }
+
+ int main() {
+ f<1>();
+ f<2>();
+
+ g<int>();
+ g<double>();
+ }
+
+ incorrectly outputs "2 2 double double " on VC++ 6.
+
+ These macros, to be used in the function parameter list, fix the
+ problem without effects on the calling syntax. For instance, in
+ the case above write:
+
+ template <int n>
+ void f(BOOST_EXPLICIT_TEMPLATE_NON_TYPE(int, n)) { ... }
+
+ template <typename T>
+ void g(BOOST_EXPLICIT_TEMPLATE_TYPE(T)) { ... }
+
+
+ Beware that they can declare (for affected compilers) a dummy
+ defaulted parameter, so they
+
a) should be always invoked *at the end* of the parameter list
+
b) can't be used if your function template is multiply declared.
+
+
+ Furthermore, in order to add any needed comma separator, an "APPEND_*"
+ version must be used when the macro invocation appears after a normal
+ parameter declaration or after the invocation of another macro of this
+ same group.
+ |
+