boost/units/io.hpp
// Boost.Units - A C++ library for zero-overhead dimensional analysis and
// unit/quantity manipulation and conversion
//
// Copyright (C) 2003-2008 Matthias Christian Schabel
// Copyright (C) 2007-2008 Steven Watanabe
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_UNITS_IO_HPP
#define BOOST_UNITS_IO_HPP
#include <cassert>
#include <string>
#include <iosfwd>
#include <ios>
#include <sstream>
#include <boost/mpl/size.hpp>
#include <boost/mpl/begin.hpp>
#include <boost/mpl/next.hpp>
#include <boost/mpl/deref.hpp>
#include <boost/serialization/nvp.hpp>
#include <boost/units/units_fwd.hpp>
#include <boost/units/heterogeneous_system.hpp>
#include <boost/units/quantity.hpp>
#include <boost/units/scale.hpp>
#include <boost/units/static_rational.hpp>
#include <boost/units/unit.hpp>
#include <boost/units/detail/utility.hpp>
namespace boost {
namespace serialization {
/// Boost Serialization library support for units.
template<class Archive,class System,class Dim>
inline void serialize(Archive& ar,boost::units::unit<Dim,System>&,const unsigned int /*version*/)
{ }
/// Boost Serialization library support for quantities.
template<class Archive,class Unit,class Y>
inline void serialize(Archive& ar,boost::units::quantity<Unit,Y>& q,const unsigned int /*version*/)
{
ar & boost::serialization::make_nvp("value", units::quantity_cast<Y&>(q));
}
} // namespace serialization
namespace units {
// get string representation of arbitrary type
template<class T> std::string to_string(const T& t)
{
std::stringstream sstr;
sstr << t;
return sstr.str();
}
// get string representation of integral-valued @c static_rational
template<integer_type N> std::string to_string(const static_rational<N>&)
{
return to_string(N);
}
// get string representation of @c static_rational
template<integer_type N, integer_type D> std::string to_string(const static_rational<N,D>&)
{
return '(' + to_string(N) + '/' + to_string(D) + ')';
}
/// Write @c static_rational to @c std::basic_ostream.
template<class Char, class Traits, integer_type N, integer_type D>
inline std::basic_ostream<Char, Traits>& operator<<(std::basic_ostream<Char, Traits>& os,const static_rational<N,D>& r)
{
os << to_string(r);
return os;
}
/// traits template for unit names
template<class BaseUnit>
struct base_unit_info
{
/// The full name of the unit (returns BaseUnit::name() by default)
static std::string name()
{
return(BaseUnit::name());
}
/// The symbol for the base unit (Returns BaseUnit::symbol() by default)
static std::string symbol()
{
return(BaseUnit::symbol());
}
};
enum format_mode
{
symbol_fmt = 0, // default - reduces unit names to known symbols for both base and derived units
name_fmt, // output full unit names for base and derived units
raw_fmt, // output only symbols for base units
typename_fmt // output demangled typenames
};
namespace detail {
template<bool>
struct xalloc_key_holder
{
static int value;
static bool initialized;
};
template<bool b>
int xalloc_key_holder<b>::value = 0;
template<bool b>
bool xalloc_key_holder<b>::initialized = 0;
struct xalloc_key_initializer_t
{
xalloc_key_initializer_t()
{
if (!xalloc_key_holder<true>::initialized)
{
xalloc_key_holder<true>::value = std::ios_base::xalloc();
xalloc_key_holder<true>::initialized = true;
}
}
};
namespace /**/ {
xalloc_key_initializer_t xalloc_key_initializer;
} // namespace
} // namespace detail
inline format_mode get_format(std::ios_base& ios)
{
return(static_cast<format_mode>(ios.iword(detail::xalloc_key_holder<true>::value)));
}
inline void set_format(std::ios_base& ios, format_mode new_mode)
{
ios.iword(detail::xalloc_key_holder<true>::value) = static_cast<long>(new_mode);
}
inline std::ios_base& typename_format(std::ios_base& ios)
{
(set_format)(ios, typename_fmt);
return(ios);
}
inline std::ios_base& raw_format(std::ios_base& ios)
{
(set_format)(ios, raw_fmt);
return(ios);
}
inline std::ios_base& symbol_format(std::ios_base& ios)
{
(set_format)(ios, symbol_fmt);
return(ios);
}
inline std::ios_base& name_format(std::ios_base& ios)
{
(set_format)(ios, name_fmt);
return(ios);
}
namespace detail {
template<integer_type N, integer_type D>
inline std::string exponent_string(const static_rational<N,D>& r)
{
return '^' + to_string(r);
}
template<>
inline std::string exponent_string(const static_rational<1>&)
{
return "";
}
template<class T>
inline std::string base_unit_symbol_string(const T&)
{
return base_unit_info<typename T::tag_type>::symbol() + exponent_string(typename T::value_type());
}
template<class T>
inline std::string base_unit_name_string(const T&)
{
return base_unit_info<typename T::tag_type>::name() + exponent_string(typename T::value_type());
}
// stringify with symbols
template<int N>
struct symbol_string_impl
{
template<class Begin>
struct apply
{
typedef typename symbol_string_impl<N-1>::template apply<typename Begin::next> next;
static void value(std::string& str)
{
str += base_unit_symbol_string(typename Begin::item()) + ' ';
next::value(str);
}
};
};
template<>
struct symbol_string_impl<1>
{
template<class Begin>
struct apply
{
static void value(std::string& str)
{
str += base_unit_symbol_string(typename Begin::item());
};
};
};
template<>
struct symbol_string_impl<0>
{
template<class Begin>
struct apply
{
static void value(std::string& str)
{
// better shorthand for dimensionless?
str += "dimensionless";
}
};
};
template<int N>
struct scale_symbol_string_impl
{
template<class Begin>
struct apply
{
static void value(std::string& str)
{
str += Begin::item::symbol();
scale_symbol_string_impl<N - 1>::template apply<typename Begin::next>::value(str);
}
};
};
template<>
struct scale_symbol_string_impl<0>
{
template<class Begin>
struct apply
{
static void value(std::string&) { }
};
};
// stringify with names
template<int N>
struct name_string_impl
{
template<class Begin>
struct apply
{
typedef typename name_string_impl<N-1>::template apply<typename Begin::next> next;
static void value(std::string& str)
{
str += base_unit_name_string(typename Begin::item()) + ' ';
next::value(str);
}
};
};
template<>
struct name_string_impl<1>
{
template<class Begin>
struct apply
{
static void value(std::string& str)
{
str += base_unit_name_string(typename Begin::item());
};
};
};
template<>
struct name_string_impl<0>
{
template<class Begin>
struct apply
{
static void value(std::string& str)
{
str += "dimensionless";
}
};
};
template<int N>
struct scale_name_string_impl
{
template<class Begin>
struct apply
{
static void value(std::string& str)
{
str += Begin::item::name();
scale_name_string_impl<N - 1>::template apply<typename Begin::next>::value(str);
}
};
};
template<>
struct scale_name_string_impl<0>
{
template<class Begin>
struct apply
{
static void value(std::string&) { }
};
};
} // namespace detail
namespace detail {
// These two overloads of symbol_string and name_string will
// will pick up homogeneous_systems. They simply call the
// appropriate function with a heterogeneous_system.
template<class Dimension,class System, class SubFormatter>
inline std::string
to_string_impl(const unit<Dimension,System>&, SubFormatter f)
{
return f(typename reduce_unit<unit<Dimension, System> >::type());
}
/// INTERNAL ONLY
// this overload picks up heterogeneous units that are not scaled.
template<class Dimension,class Units, class Subformatter>
inline std::string
to_string_impl(const unit<Dimension, heterogeneous_system<heterogeneous_system_impl<Units, Dimension, dimensionless_type> > >&, Subformatter f)
{
std::string str;
f.template append_units_to<Units>(str);
return(str);
}
// This overload is a special case for heterogeneous_system which
// is really unitless
/// INTERNAL ONLY
template<class Subformatter>
inline std::string
to_string_impl(const unit<dimensionless_type, heterogeneous_system<heterogeneous_system_impl<dimensionless_type, dimensionless_type, dimensionless_type> > >&, Subformatter)
{
return("dimensionless");
}
// this overload deals with heterogeneous_systems which are unitless
// but scaled.
/// INTERNAL ONLY
template<class Scale, class Subformatter>
inline std::string
to_string_impl(const unit<dimensionless_type, heterogeneous_system<heterogeneous_system_impl<dimensionless_type, dimensionless_type, Scale> > >&, Subformatter f)
{
std::string str;
f.template append_scale_to<Scale>(str);
return(str);
}
// this overload deals with scaled units.
/// INTERNAL ONLY
template<class Dimension,class Units,class Scale, class Subformatter>
inline std::string
to_string_impl(const unit<Dimension, heterogeneous_system<heterogeneous_system_impl<Units, Dimension, Scale> > >&, Subformatter f)
{
std::string str;
f.template append_scale_to<Scale>(str);
std::string without_scale = f(unit<Dimension, heterogeneous_system<heterogeneous_system_impl<Units, Dimension, dimensionless_type> > >());
if (f.is_default_string(without_scale, unit<Dimension, heterogeneous_system<heterogeneous_system_impl<Units, Dimension, dimensionless_type> > >()))
{
str += "(";
str += without_scale;
str += ")";
}
else
{
str += without_scale;
}
return(str);
}
// this overload catches scaled units that have a single base unit
// raised to the first power. It causes si::nano * si::meters to not
// put parentheses around the meters. i.e. nm rather than n(m)
/// INTERNAL ONLY
template<class Dimension,class Unit,class Scale, class Subformatter>
inline std::string
to_string_impl(const unit<Dimension, heterogeneous_system<heterogeneous_system_impl<list<heterogeneous_system_dim<Unit, static_rational<1> >,dimensionless_type>, Dimension, Scale> > >&, Subformatter f)
{
std::string str;
f.template append_scale_to<Scale>(str);
str += f(unit<Dimension, heterogeneous_system<heterogeneous_system_impl<list<heterogeneous_system_dim<Unit, static_rational<1> >, dimensionless_type>, Dimension, dimensionless_type> > >());
return(str);
}
// this overload is necessary to disambiguate.
// it catches units that are unscaled and have a single
// base unit raised to the first power. It is treated the
// same as any other unscaled unit.
/// INTERNAL ONLY
template<class Dimension,class Unit,class Subformatter>
inline std::string
to_string_impl(const unit<Dimension, heterogeneous_system<heterogeneous_system_impl<list<heterogeneous_system_dim<Unit, static_rational<1> >,dimensionless_type>, Dimension, dimensionless_type> > >&, Subformatter f)
{
std::string str;
f.template append_units_to<list<heterogeneous_system_dim<Unit, static_rational<1> >,dimensionless_type> >(str);
return(str);
}
// this overload catches scaled units that have a single scaled base unit
// raised to the first power. It moves that scaling on the base unit
// to the unit level scaling and recurses. By doing this we make sure that
// si::milli * si::kilograms will print g rather than mkg
//
/// INTERNAL ONLY
template<class Dimension,class Unit,class UnitScale, class Scale, class Subformatter>
inline std::string
to_string_impl(const unit<Dimension, heterogeneous_system<heterogeneous_system_impl<list<heterogeneous_system_dim<scaled_base_unit<Unit, UnitScale>, static_rational<1> >, dimensionless_type>, Dimension, Scale> > >&, Subformatter f)
{
return(f(
unit<
Dimension,
heterogeneous_system<
heterogeneous_system_impl<
list<heterogeneous_system_dim<Unit, static_rational<1> >, dimensionless_type>,
Dimension,
typename mpl::times<Scale, list<UnitScale, dimensionless_type> >::type
>
>
>()));
}
// this overload disambuguates between the overload for an unscaled unit
// and the overload for a scaled base unit raised to the first power.
/// INTERNAL ONLY
template<class Dimension,class Unit,class UnitScale,class Subformatter>
inline std::string
to_string_impl(const unit<Dimension, heterogeneous_system<heterogeneous_system_impl<list<heterogeneous_system_dim<scaled_base_unit<Unit, UnitScale>, static_rational<1> >, dimensionless_type>, Dimension, dimensionless_type> > >&, Subformatter f)
{
std::string str;
f.template append_units_to<list<heterogeneous_system_dim<scaled_base_unit<Unit, UnitScale>, static_rational<1> >, dimensionless_type> >(str);
return(str);
}
struct format_raw_symbol_impl {
template<class Units>
void append_units_to(std::string& str) {
detail::symbol_string_impl<Units::size::value>::template apply<Units>::value(str);
}
template<class Scale>
void append_scale_to(std::string& str) {
detail::scale_symbol_string_impl<Scale::size::value>::template apply<Scale>::value(str);
}
template<class Unit>
std::string operator()(const Unit& unit) {
return(to_string_impl(unit, *this));
}
template<class Unit>
bool is_default_string(const std::string&, const Unit&) {
return(true);
}
};
struct format_symbol_impl : format_raw_symbol_impl {
template<class Unit>
std::string operator()(const Unit& unit) {
return(symbol_string(unit));
}
template<class Unit>
bool is_default_string(const std::string& str, const Unit& unit) {
return(str == to_string_impl(unit, format_raw_symbol_impl()));
}
};
struct format_raw_name_impl {
template<class Units>
void append_units_to(std::string& str) {
detail::name_string_impl<(Units::size::value)>::template apply<Units>::value(str);
}
template<class Scale>
void append_scale_to(std::string& str) {
detail::scale_name_string_impl<Scale::size::value>::template apply<Scale>::value(str);
}
template<class Unit>
std::string operator()(const Unit& unit) {
return(to_string_impl(unit, *this));
}
template<class Unit>
bool is_default_string(const std::string&, const Unit&) {
return(true);
}
};
struct format_name_impl : format_raw_name_impl {
template<class Unit>
std::string operator()(const Unit& unit) {
return(name_string(unit));
}
template<class Unit>
bool is_default_string(const std::string& str, const Unit& unit) {
return(str == to_string_impl(unit, format_raw_name_impl()));
}
};
} // namespace detail
template<class Dimension,class System>
inline std::string
typename_string(const unit<Dimension, System>&)
{
return simplify_typename(typename reduce_unit< unit<Dimension,System> >::type());
}
template<class Dimension,class System>
inline std::string
symbol_string(const unit<Dimension, System>&)
{
return detail::to_string_impl(unit<Dimension,System>(), detail::format_symbol_impl());
}
template<class Dimension,class System>
inline std::string
name_string(const unit<Dimension, System>&)
{
return detail::to_string_impl(unit<Dimension,System>(), detail::format_name_impl());
}
/// Print an @c unit as a list of base units and exponents
///
/// for @c symbol_format this gives e.g. "m s^-1" or "J"
/// for @c name_format this gives e.g. "meter second^-1" or "joule"
/// for @c raw_format this gives e.g. "m s^-1" or "meter kilogram^2 second^-2"
/// for @c typename_format this gives the typename itself (currently demangled only on GCC)
template<class Char, class Traits, class Dimension, class System>
inline std::basic_ostream<Char, Traits>& operator<<(std::basic_ostream<Char, Traits>& os, const unit<Dimension, System>& u)
{
if (units::get_format(os) == typename_fmt)
{
os << typename_string(u);
}
else if (units::get_format(os) == raw_fmt)
{
os << detail::to_string_impl(u, detail::format_raw_symbol_impl());
}
else if (units::get_format(os) == symbol_fmt)
{
os << symbol_string(u);
}
else if (units::get_format(os) == name_fmt)
{
os << name_string(u);
}
else
{
assert(!"The format mode must be one of: typename_format, raw_format, name_format, symbol_format");
}
return(os);
}
/// INTERNAL ONLY
/// Print a @c quantity. Prints the value followed by the unit
template<class Char, class Traits, class Unit, class T>
inline std::basic_ostream<Char, Traits>& operator<<(std::basic_ostream<Char, Traits>& os, const quantity<Unit, T>& q)
{
os << q.value() << ' ' << Unit();
return(os);
}
} // namespace units
} // namespace boost
#endif