- prepared for 1.0.13 release

[ginac.git] / ginac / ex.h

diff --git a/ginac/ex.h b/ginac/ex.h
index f119c85b5fb93b66c81af6461ca10457bc315a6b..208151df99fbc97616bbc1d74b3b89f5b1de187f 100644 (file)
--- a/ginac/ex.h
+++ b/ginac/ex.h
@@ -3,7 +3,7 @@
  *  Interface to GiNaC's light-weight expression handles. */
 
 /*
- *  GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2003 Johannes Gutenberg University Mainz, Germany
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -23,11 +23,12 @@
 #ifndef __GINAC_EX_H__
 #define __GINAC_EX_H__
 
+#include <iosfwd>
+#include <functional>
+
 #include "basic.h"
 #include "operators.h"
 
-#include <functional>
-
 namespace GiNaC {
 
 /** Helper class to initialize the library.  There must be one static object
@@ -74,7 +75,7 @@ class ex
        
 // member functions
        
-       // default ctor, dtor, copy ctor assignment operator and helpers
+       // default ctor, dtor, copy ctor, assignment operator and helpers
 public:
        ex();
        ~ex();
@@ -88,15 +89,28 @@ public:
        ex(long i);
        ex(unsigned long i);
        ex(double const d);
+
        /** Construct ex from string and a list of symbols. The input grammar is
-        *  similar to the GiNaC output format. All symbols to be used in the
-        *  expression must be specified in a lst in the second argument. Undefined
-        *  symbols and other parser errors will throw an exception. */
+        *  similar to the GiNaC output format. All symbols and indices to be used
+        *  in the expression must be specified in a lst in the second argument.
+        *  Undefined symbols and other parser errors will throw an exception. */
        ex(const std::string &s, const ex &l);
        
        // non-virtual functions in this class
 public:
-       void swap(ex & other);
+       /** Efficiently swap the contents of two expressions. */
+       void swap(ex & other)
+       {
+               GINAC_ASSERT(bp!=0);
+               GINAC_ASSERT(bp->flags & status_flags::dynallocated);
+               GINAC_ASSERT(other.bp!=0);
+               GINAC_ASSERT(other.bp->flags & status_flags::dynallocated);
+       
+               basic * tmpbp = bp;
+               bp = other.bp;
+               other.bp = tmpbp;
+       }
+
        void print(const print_context & c, unsigned level = 0) const;
        void printtree(std::ostream & os) const;
        void dbgprint(void) const;
@@ -210,7 +224,6 @@ public:
 inline
 ex::ex()
 {
-       /* debugmsg("ex default ctor",LOGLEVEL_CONSTRUCT); */
        extern const class numeric *_num0_p;
        bp = (basic*)_num0_p;
        GINAC_ASSERT(bp!=0);
@@ -224,7 +237,6 @@ ex::ex()
 inline
 ex::~ex()
 {
-       /*debugmsg("ex dtor",LOGLEVEL_DESTRUCT);*/
        GINAC_ASSERT(bp!=0);
        GINAC_ASSERT(bp->flags & status_flags::dynallocated);
        if (--bp->refcount == 0)
@@ -234,7 +246,6 @@ ex::~ex()
 inline
 ex::ex(const ex & other) : bp(other.bp)
 {
-       /*debugmsg("ex copy ctor",LOGLEVEL_CONSTRUCT);*/
        GINAC_ASSERT(bp!=0);
        GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
        ++bp->refcount;
@@ -246,7 +257,6 @@ ex::ex(const ex & other) : bp(other.bp)
 inline
 ex & ex::operator=(const ex & other)
 {
-       /*debugmsg("ex operator=",LOGLEVEL_ASSIGNMENT);*/
        GINAC_ASSERT(bp!=0);
        GINAC_ASSERT(bp->flags & status_flags::dynallocated);
        GINAC_ASSERT(other.bp!=0);
@@ -265,7 +275,6 @@ ex & ex::operator=(const ex & other)
 inline
 ex::ex(const basic & other)
 {
-       /*debugmsg("ex ctor from basic",LOGLEVEL_CONSTRUCT);*/
        construct_from_basic(other);
 #ifdef OBSCURE_CINT_HACK
        update_last_created_or_assigned_bp();
@@ -275,7 +284,6 @@ ex::ex(const basic & other)
 inline
 ex::ex(int i)
 {
-       /*debugmsg("ex ctor from int",LOGLEVEL_CONSTRUCT);*/
        construct_from_int(i);
 #ifdef OBSCURE_CINT_HACK
        update_last_created_or_assigned_bp();
@@ -285,7 +293,6 @@ ex::ex(int i)
 inline
 ex::ex(unsigned int i)
 {
-       /*debugmsg("ex ctor from unsigned int",LOGLEVEL_CONSTRUCT);*/
        construct_from_uint(i);
 #ifdef OBSCURE_CINT_HACK
        update_last_created_or_assigned_bp();
@@ -295,7 +302,6 @@ ex::ex(unsigned int i)
 inline
 ex::ex(long i)
 {
-       /*debugmsg("ex ctor from long",LOGLEVEL_CONSTRUCT);*/
        construct_from_long(i);
 #ifdef OBSCURE_CINT_HACK
        update_last_created_or_assigned_bp();
@@ -305,7 +311,6 @@ ex::ex(long i)
 inline
 ex::ex(unsigned long i)
 {
-       /*debugmsg("ex ctor from unsigned long",LOGLEVEL_CONSTRUCT);*/
        construct_from_ulong(i);
 #ifdef OBSCURE_CINT_HACK
        update_last_created_or_assigned_bp();
@@ -315,7 +320,6 @@ ex::ex(unsigned long i)
 inline
 ex::ex(double const d)
 {
-       /*debugmsg("ex ctor from double",LOGLEVEL_CONSTRUCT);*/
        construct_from_double(d);
 #ifdef OBSCURE_CINT_HACK
        update_last_created_or_assigned_bp();
@@ -325,7 +329,6 @@ ex::ex(double const d)
 inline
 ex::ex(const std::string &s, const ex &l)
 {
-       /*debugmsg("ex ctor from string,lst",LOGLEVEL_CONSTRUCT);*/
        construct_from_string_and_lst(s, l);
 #ifdef OBSCURE_CINT_HACK
        update_last_created_or_assigned_bp();
@@ -354,6 +357,11 @@ bool ex::is_equal(const ex & other) const
 
 
 // utility functions
+
+/** Compare two objects of class quickly without doing a deep tree traversal.
+ *  @return "true" if they are equal
+ *          "false" if equality cannot be established quickly (e1 and e2 may
+ *          still be equal, in this case. */
 inline bool are_ex_trivially_equal(const ex &e1, const ex &e2)
 {
        return e1.bp == e2.bp;
@@ -462,6 +470,10 @@ inline bool is_zero(const ex & thisex)
 inline void swap(ex & e1, ex & e2)
 { e1.swap(e2); }
 
+// This makes STL algorithms use the more efficient swap operation for ex objects
+inline void iter_swap(std::vector<ex>::iterator i1, std::vector<ex>::iterator i2)
+{ i1->swap(*i2); }
+
 
 /* Function objects for STL sort() etc. */
 struct ex_is_less : public std::binary_function<ex, ex, bool> {