Module: ppl/ppl Branch: master Commit: 6f07d12fc19f7b867a5b43f6f143f2fd202ff928 URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=6f07d12fc19f7... Author: Enea Zaffanella <zaffanella@cs.unipr.it> Date: Thu Mar 25 12:00:22 2010 +0100 Added helper function sub_mul_assign() to Linear_Expression interface. --- src/Linear_Expression.cc | 19 +++++++++++++++++++ src/Linear_Expression.defs.hh | 9 +++++++++ 2 files changed, 28 insertions(+), 0 deletions(-) diff --git a/src/Linear_Expression.cc b/src/Linear_Expression.cc index f7d50a3..cd8ace8 100644 --- a/src/Linear_Expression.cc +++ b/src/Linear_Expression.cc @@ -373,6 +373,25 @@ PPL::add_mul_assign(Linear_Expression& e, return e; } +/*! \relates Parma_Polyhedra_Library::Linear_Expression */ +PPL::Linear_Expression& +PPL::sub_mul_assign(Linear_Expression& e, + Coefficient_traits::const_reference n, + const Variable v) { + const dimension_type v_space_dim = v.space_dimension(); + if (v_space_dim > Linear_Expression::max_space_dimension()) + throw std::length_error("Linear_Expression& " + "PPL::sub_mul_assign(e, n, v):\n" + "v exceeds the maximum allowed space dimension."); + const dimension_type e_size = e.size(); + if (e_size <= v_space_dim) { + Linear_Expression new_e(e, v_space_dim+1); + e.swap(new_e); + } + e[v_space_dim] -= n; + return e; +} + bool PPL::Linear_Expression::OK() const { return Linear_Row::OK(); diff --git a/src/Linear_Expression.defs.hh b/src/Linear_Expression.defs.hh index 5e4c81d..222ba57 100644 --- a/src/Linear_Expression.defs.hh +++ b/src/Linear_Expression.defs.hh @@ -172,6 +172,12 @@ Linear_Expression& add_mul_assign(Linear_Expression& e, Coefficient_traits::const_reference n, Variable v); +//! Returns the linear expression \p e - \p n * \p v and assigns it to \p e. +/*! \relates Linear_Expression */ +Linear_Expression& +sub_mul_assign(Linear_Expression& e, + Coefficient_traits::const_reference n, Variable v); + namespace IO_Operators { //! Output operator. @@ -469,6 +475,9 @@ private: friend Linear_Expression& add_mul_assign(Linear_Expression& e, Coefficient_traits::const_reference n, Variable v); + friend Linear_Expression& + sub_mul_assign(Linear_Expression& e, + Coefficient_traits::const_reference n, Variable v); friend std::ostream& Parma_Polyhedra_Library::IO_Operators