another safety belt

[lyx.git] / src / support / lyxfunctional.h

diff --git a/src/support/lyxfunctional.h b/src/support/lyxfunctional.h
index 5eedb9098b236406d90e13ab322572eeccc6a01e..c89e097621e12b4de89d63bf2d9a41e755b79aff 100644 (file)
--- a/src/support/lyxfunctional.h
+++ b/src/support/lyxfunctional.h
@@ -3,41 +3,42 @@
 #ifndef LYX_FUNCTIONAL_H
 #define LYX_FUNCTIONAL_H
 
-//namespace lyx {
+/** \file lyxfunctional.h
+    \brief Convenient function objects for use with LyX
 
-template<class R, class C, class A>
-class class_fun_t {
-public:
-       class_fun_t(C & ct, R(C::*p)(A)) 
-               : c(ct), cmf(p) {}
-       R operator()(A & a) const {
-               return (c.*cmf)(a);
-       }
-private:
-       C & c;
-       R(C::*cmf)(A);
-};
+    This is currently a small collection of small function objects for use
+    together with std::algorithms.
+**/
 
+#include <iterator>
 
-template <class R, class C, class A> class_fun_t<R, C, A>
-class_fun(C & c, R(C::*f)(A))
-{
-       return class_fun_t<R, C, A>(c, f);
-}
-
+namespace lyx {
 
 template <class Cont, class Type, class MemRet>
 class back_insert_fun_iterator {
 protected:
-       Cont & container;
+       Cont * container;
        MemRet(Type::*pmf)();
 public:
+       typedef Cont container_type;
+       typedef std::output_iterator_tag iterator_category;
+       typedef void value_type;
+       typedef void difference_type;
+       typedef void pointer;
+       typedef void reference;
+
        back_insert_fun_iterator(Cont & x, MemRet(Type::*p)())
-               : container(x), pmf(p) {}
+               : container(&x), pmf(p) {}
 
        back_insert_fun_iterator &
        operator=(Type * val) {
-               container.push_back((val->*pmf)());
+               container->push_back((val->*pmf)());
+               return *this;
+       }
+
+       back_insert_fun_iterator &
+       operator=(Type & val) {
+               container->push_back((val.*pmf)());
                return *this;
        }
 
@@ -53,6 +54,48 @@ public:
 };
 
 
+template <class Cont, class Type, class MemRet>
+class const_back_insert_fun_iterator {
+protected:
+       Cont * container;
+       MemRet(Type::*pmf)() const;
+public:
+       typedef Cont container_type;
+       typedef std::output_iterator_tag iterator_category;
+       typedef void value_type;
+       typedef void difference_type;
+       typedef void pointer;
+       typedef void reference;
+
+       const_back_insert_fun_iterator(Cont & x, MemRet(Type::*p)() const)
+               : container(&x), pmf(p) {}
+
+       ~const_back_insert_fun_iterator() {}
+
+       const_back_insert_fun_iterator &
+       operator=(Type const * val) {
+               container->push_back((val->*pmf)());
+               return *this;
+       }
+
+       const_back_insert_fun_iterator &
+       operator=(Type const & val) {
+               container->push_back((val.*pmf)());
+               return *this;
+       }
+
+       const_back_insert_fun_iterator & operator*() {
+               return *this;
+       }
+       const_back_insert_fun_iterator & operator++() { // prefix ++
+               return *this;
+       }
+       const_back_insert_fun_iterator & operator++(int) { // postfix ++
+               return *this;
+       }
+};
+
+
 template <class Cont, class Type, class MemRet>
 back_insert_fun_iterator<Cont, Type, MemRet>
 back_inserter_fun(Cont & cont, MemRet(Type::*p)())
@@ -61,6 +104,14 @@ back_inserter_fun(Cont & cont, MemRet(Type::*p)())
 }
 
 
+template <class Cont, class Type, class MemRet>
+const_back_insert_fun_iterator<Cont, Type, MemRet>
+back_inserter_fun(Cont & cont, MemRet(Type::*p)() const)
+{
+       return const_back_insert_fun_iterator<Cont, Type, MemRet>(cont, p);
+}
+
+
 template <class R, class C, class A>
 class compare_memfun_t {
 public:
@@ -78,6 +129,23 @@ private:
 };
 
 
+template <class R, class C, class A>
+class const_compare_memfun_t {
+public:
+       const_compare_memfun_t(R(C::*p)() const, A const & a)
+               : pmf(p), arg(a) {}
+       bool operator()(C const * c) {
+               return (c->*pmf)() == arg;
+       }
+       bool operator()(C const & c) {
+               return (c.*pmf)() == arg;
+       }
+private:
+       R(C::*pmf)() const;
+       A const & arg;
+};
+
+
 template <class R, class C, class A>
 compare_memfun_t<R, C, A>
 compare_memfun(R(C::*p)(), A const & a)
@@ -85,44 +153,55 @@ compare_memfun(R(C::*p)(), A const & a)
        return compare_memfun_t<R, C, A>(p, a);
 }
 
-       
+
+template <class R, class C, class A>
+const_compare_memfun_t<R, C, A>
+compare_memfun(R(C::*p)() const, A const & a)
+{
+       return const_compare_memfun_t<R, C, A>(p, a);
+}
+
+
 // Functors used in the template.
 
 ///
-template<typename T1, typename T2>
+template<typename T>
 class equal_1st_in_pair {
 public:
        ///
-       equal_1st_in_pair(T1 const & value) : value_(value) {}
+       typedef typename T::first_type first_type;
        ///
-       typedef std::pair<T1, T2> pair_type;
+       typedef T pair_type;
+       ///
+       equal_1st_in_pair(first_type const & value) : value_(value) {}
        ///
        bool operator() (pair_type const & p) const {
                return p.first == value_;
        }
 private:
        ///
-       T1 const & value_;
+       first_type const & value_;
 };
 
 
 ///
-template<typename T1, typename T2>
+template<typename T>
 class equal_2nd_in_pair {
 public:
        ///
-       equal_2nd_in_pair(T2 const & value) : value_(value) {}
+       typedef typename T::second_type second_type;
+       ///
+       typedef T pair_type;
        ///
-       typedef std::pair<T1, T2> pair_type;
+       equal_2nd_in_pair(second_type const & value) : value_(value) {}
        ///
        bool operator() (pair_type const & p) const {
                return p.second == value_;
        }
 private:
        ///
-       T2 const & value_;
+       second_type const & value_;
 };
 
-
-// }  // end of namespace lyx
+}  // end of namespace lyx
 #endif