help compiler to apply RVO ( return the same object by value)

This commit is contained in:
artemp 2015-04-08 13:10:22 +02:00
parent 431c581759
commit 310865a0c3

View file

@ -29,7 +29,7 @@ namespace mapnik {
namespace geometry { namespace geometry {
namespace detail { namespace detail {
geometry_empty reproject_internal(geometry_empty const&, proj_transform const&, unsigned int &) geometry_empty reproject_internal(geometry_empty const&, proj_transform const&, unsigned int &)
{ {
return geometry_empty(); return geometry_empty();
@ -55,7 +55,7 @@ line_string reproject_internal(line_string const & ls, proj_transform const& pro
} }
return new_ls; return new_ls;
} }
polygon reproject_internal(polygon const & poly, proj_transform const& proj_trans, unsigned int & n_err) polygon reproject_internal(polygon const & poly, proj_transform const& proj_trans, unsigned int & n_err)
{ {
polygon new_poly; polygon new_poly;
@ -87,7 +87,7 @@ polygon reproject_internal(polygon const & poly, proj_transform const& proj_tran
} }
return new_poly; return new_poly;
} }
multi_point reproject_internal(multi_point const & mp, proj_transform const& proj_trans, unsigned int & n_err) multi_point reproject_internal(multi_point const & mp, proj_transform const& proj_trans, unsigned int & n_err)
{ {
multi_point new_mp; multi_point new_mp;
@ -131,7 +131,7 @@ multi_line_string reproject_internal(multi_line_string const & mls, proj_transfo
} }
return new_mls; return new_mls;
} }
multi_polygon reproject_internal(multi_polygon const & mpoly, proj_transform const& proj_trans, unsigned int & n_err) multi_polygon reproject_internal(multi_polygon const & mpoly, proj_transform const& proj_trans, unsigned int & n_err)
{ {
multi_polygon new_mpoly; multi_polygon new_mpoly;
@ -146,7 +146,7 @@ multi_polygon reproject_internal(multi_polygon const & mpoly, proj_transform con
} }
return new_mpoly; return new_mpoly;
} }
geometry_collection reproject_internal(geometry_collection const & c, proj_transform const& proj_trans, unsigned int & n_err) geometry_collection reproject_internal(geometry_collection const & c, proj_transform const& proj_trans, unsigned int & n_err)
{ {
geometry_collection new_c; geometry_collection new_c;
@ -165,87 +165,80 @@ geometry_collection reproject_internal(geometry_collection const & c, proj_trans
struct geom_reproj_copy_visitor { struct geom_reproj_copy_visitor {
geom_reproj_copy_visitor(proj_transform const & proj_trans, unsigned int & n_err) geom_reproj_copy_visitor(proj_transform const & proj_trans, unsigned int & n_err)
: proj_trans_(proj_trans), : proj_trans_(proj_trans),
n_err_(n_err) {} n_err_(n_err) {}
geometry operator() (geometry_empty const&) geometry operator() (geometry_empty const&)
{ {
return std::move(geometry_empty()); return geometry_empty();
} }
geometry operator() (point const& p) geometry operator() (point const& p)
{ {
geometry geom; // default empty
unsigned int intial_err = n_err_; unsigned int intial_err = n_err_;
point new_p = reproject_internal(p, proj_trans_, n_err_); point new_p = reproject_internal(p, proj_trans_, n_err_);
if (n_err_ > intial_err) if (n_err_ > intial_err) return geom;
{ geom = std::move(new_p);
return std::move(geometry_empty()); return geom;
}
return std::move(new_p);
} }
geometry operator() (line_string const& ls) geometry operator() (line_string const& ls)
{ {
geometry geom; // default empty
int intial_err = n_err_; int intial_err = n_err_;
line_string new_ls = reproject_internal(ls, proj_trans_, n_err_); line_string new_ls = reproject_internal(ls, proj_trans_, n_err_);
if (n_err_ > intial_err || new_ls.empty()) if (n_err_ > intial_err || new_ls.empty()) return geom;
{ geom = std::move(new_ls);
return std::move(geometry_empty()); return geom;
}
return std::move(new_ls);
}
geometry operator() (polygon const& poly)
{
polygon new_poly = reproject_internal(poly, proj_trans_, n_err_);
if (new_poly.exterior_ring.empty())
{
return std::move(geometry_empty());
}
return std::move(new_poly);
}
geometry operator() (multi_point const& mp)
{
multi_point new_mp = reproject_internal(mp, proj_trans_, n_err_);
if (new_mp.empty())
{
return std::move(geometry_empty());
}
return std::move(new_mp);
}
geometry operator() (multi_line_string const& mls)
{
multi_line_string new_mls = reproject_internal(mls, proj_trans_, n_err_);
if (new_mls.empty())
{
return std::move(geometry_empty());
}
return std::move(new_mls);
}
geometry operator() (multi_polygon const& mpoly)
{
multi_polygon new_mpoly = reproject_internal(mpoly, proj_trans_, n_err_);
if (new_mpoly.empty())
{
return std::move(geometry_empty());
}
return std::move(new_mpoly);
}
geometry operator() (geometry_collection const& c)
{
geometry_collection new_c = reproject_internal(c, proj_trans_, n_err_);
if (new_c.empty())
{
return std::move(geometry_empty());
}
return std::move(new_c);
} }
private: geometry operator() (polygon const& poly)
{
geometry geom; // default empty
polygon new_poly = reproject_internal(poly, proj_trans_, n_err_);
if (new_poly.exterior_ring.empty()) return geom;
geom = std::move(new_poly);
return geom;
}
geometry operator() (multi_point const& mp)
{
geometry geom; // default empty
multi_point new_mp = reproject_internal(mp, proj_trans_, n_err_);
if (new_mp.empty()) return geom;
geom = std::move(new_mp);
return geom;
}
geometry operator() (multi_line_string const& mls)
{
geometry geom; // default empty
multi_line_string new_mls = reproject_internal(mls, proj_trans_, n_err_);
if (new_mls.empty()) return geom;
geom = std::move(new_mls);
return geom;
}
geometry operator() (multi_polygon const& mpoly)
{
geometry geom; // default empty
multi_polygon new_mpoly = reproject_internal(mpoly, proj_trans_, n_err_);
if (new_mpoly.empty()) return geom;
geom = std::move(new_mpoly);
return geom;
}
geometry operator() (geometry_collection const& c)
{
geometry geom; // default empty
geometry_collection new_c = reproject_internal(c, proj_trans_, n_err_);
if (new_c.empty()) return geom;
geom = std::move(new_c);
return geom;
}
private:
proj_transform const& proj_trans_; proj_transform const& proj_trans_;
unsigned int & n_err_; unsigned int & n_err_;
@ -304,7 +297,7 @@ struct geom_reproj_visitor {
} }
bool operator() (geometry_empty &) { return true; } bool operator() (geometry_empty &) { return true; }
bool operator() (point & p) bool operator() (point & p)
{ {
if (!proj_trans_.forward(p)) if (!proj_trans_.forward(p))
@ -329,7 +322,7 @@ struct geom_reproj_visitor {
{ {
return false; return false;
} }
for (auto & lr : poly.interior_rings) for (auto & lr : poly.interior_rings)
{ {
if (proj_trans_.forward(lr) > 0) if (proj_trans_.forward(lr) > 0)
@ -339,12 +332,12 @@ struct geom_reproj_visitor {
} }
return true; return true;
} }
bool operator() (multi_point & mp) bool operator() (multi_point & mp)
{ {
return (*this) (static_cast<line_string &>(mp)); return (*this) (static_cast<line_string &>(mp));
} }
bool operator() (multi_line_string & mls) bool operator() (multi_line_string & mls)
{ {
for (auto & ls : mls) for (auto & ls : mls)
@ -356,7 +349,7 @@ struct geom_reproj_visitor {
} }
return true; return true;
} }
bool operator() (multi_polygon & mpoly) bool operator() (multi_polygon & mpoly)
{ {
for (auto & poly : mpoly) for (auto & poly : mpoly)
@ -368,7 +361,7 @@ struct geom_reproj_visitor {
} }
return true; return true;
} }
bool operator() (geometry_collection & c) bool operator() (geometry_collection & c)
{ {
for (auto & g : c) for (auto & g : c)
@ -381,7 +374,7 @@ struct geom_reproj_visitor {
return true; return true;
} }
private: private:
proj_transform const& proj_trans_; proj_transform const& proj_trans_;
}; };