An absolute point on a logarithmic scale, relative to a reference. More...

#include <electro/decibel.hpp>

Public Types
using	reference = Reference
	The reference tag type.

using	rep = Rep
	The representation type.

using	precision = typename Precision::type
	The offset precision, in dB, as a std::ratio.

using	offset = gain< Rep, Precision >
	The gain type measuring the offset from the reference.

Public Member Functions
constexpr	level ()=default
	Constructs a level at the reference point (0 dB offset).

	level (const level &)=default

template<typename Rep2 > requires std::convertible_to<const Rep2&, rep> && (treat_as_inexact_v<rep> \|\| !treat_as_inexact_v<Rep2>)
constexpr	level (const Rep2 &r)
	Constructs from an offset count in dB.

constexpr	level (const offset &o)
	Constructs from an offset relative to the reference.

template<typename Rep2 , typename Precision2 > requires std::convertible_to<gain<Rep2, Precision2>, offset>
constexpr	level (const level< Reference, Rep2, Precision2 > &l)
	Converts from a level with the same reference.

template<typename Rep2 , typename Precision2 > requires (!std::is_same_v<level, level<Reference, Rep2, Precision2>>) && (!std::convertible_to<gain<Rep2, Precision2>, offset>) && std::constructible_from<offset, gain<Rep2, Precision2>>
constexpr	level (const level< Reference, Rep2, Precision2 > &l)
	Explicit constructor for lossy precision conversions.

	~level ()=default

level &	operator= (const level &)=default

constexpr offset	offset_from_reference () const
	Returns the offset from the reference point.

constexpr rep	count () const
	Returns the raw offset count, in units of Precision.

constexpr level	operator- () const
	Reflects the level about its reference point.

constexpr level	operator+ () const

constexpr level &	operator+= (const offset &o)

constexpr level &	operator-= (const offset &o)

Static Public Member Functions
static constexpr level	reference_level () noexcept
	Returns the reference point itself (a 0 dB offset).

static constexpr level	min () noexcept
	Returns the minimum representable level.

static constexpr level	max () noexcept
	Returns the maximum representable level.

Detailed Description

template<typename Reference, typename Rep, typename Precision>
class electro::level< Reference, Rep, Precision >

An absolute point on a logarithmic scale, relative to a reference.

The time_point analog: a level plus or minus a gain is a level, and the difference of two levels is a gain. Adding two levels, or scaling a level by a scalar, is deliberately ill-formed.

dbm signal{-73};                  // -73 dBm
auto amplified = signal + 20_dB;  // -53 dBm
auto delta = amplified - signal;  // 20 dB

Template Parameters

Reference	The reference tag (milliwatt_reference, ...).
Rep	Arithmetic type for the offset count.
Precision	A std::ratio giving the offset precision, in dB.

Definition at line 212 of file decibel.hpp.

Member Typedef Documentation

◆ offset

template<typename Reference , typename Rep , typename Precision >

using electro::level< Reference, Rep, Precision >::offset = gain<Rep, Precision>

The gain type measuring the offset from the reference.

Definition at line 223 of file decibel.hpp.

◆ precision

template<typename Reference , typename Rep , typename Precision >

using electro::level< Reference, Rep, Precision >::precision = typename Precision::type

The offset precision, in dB, as a std::ratio.

Definition at line 221 of file decibel.hpp.

◆ reference

template<typename Reference , typename Rep , typename Precision >

using electro::level< Reference, Rep, Precision >::reference = Reference

The reference tag type.

Definition at line 217 of file decibel.hpp.

◆ rep

template<typename Reference , typename Rep , typename Precision >

using electro::level< Reference, Rep, Precision >::rep = Rep

The representation type.

Definition at line 219 of file decibel.hpp.

Constructor & Destructor Documentation

◆ level() [1/6]

template<typename Reference , typename Rep , typename Precision >

constexpr electro::level< Reference, Rep, Precision >::level ( )

constexprdefault

Constructs a level at the reference point (0 dB offset).

Referenced by electro::level< Reference, Rep, Precision >::max(), electro::level< Reference, Rep, Precision >::min(), electro::level< Reference, Rep, Precision >::operator-(), and electro::level< Reference, Rep, Precision >::reference_level().

◆ level() [2/6]

template<typename Reference , typename Rep , typename Precision >

electro::level< Reference, Rep, Precision >::level ( const level< Reference, Rep, Precision > & )

default

◆ level() [3/6]

template<typename Reference , typename Rep , typename Precision >

template<typename Rep2 >
requires std::convertible_to<const Rep2&, rep> && (treat_as_inexact_v<rep> || !treat_as_inexact_v<Rep2>)

constexpr electro::level< Reference, Rep, Precision >::level ( const Rep2 & r )

inlineexplicitconstexpr

Constructs from an offset count in dB.

Always explicit: a bare number is not a level.

Template Parameters

Rep2	The source representation type.

Parameters

r	The offset from the reference, in units of Precision.

Definition at line 239 of file decibel.hpp.

◆ level() [4/6]

template<typename Reference , typename Rep , typename Precision >

constexpr electro::level< Reference, Rep, Precision >::level ( const offset & o )

inlineexplicitconstexpr

Constructs from an offset relative to the reference.

Definition at line 243 of file decibel.hpp.

◆ level() [5/6]

template<typename Reference , typename Rep , typename Precision >

template<typename Rep2 , typename Precision2 >
requires std::convertible_to<gain<Rep2, Precision2>, offset>

constexpr electro::level< Reference, Rep, Precision >::level ( const level< Reference, Rep2, Precision2 > & l )

inlineconstexpr

Converts from a level with the same reference.

Implicit when the conversion is lossless, mirroring quantity.

Definition at line 253 of file decibel.hpp.

◆ level() [6/6]

template<typename Reference , typename Rep , typename Precision >

template<typename Rep2 , typename Precision2 >
requires (!std::is_same_v<level, level<Reference, Rep2, Precision2>>) && (!std::convertible_to<gain<Rep2, Precision2>, offset>) && std::constructible_from<offset, gain<Rep2, Precision2>>

constexpr electro::level< Reference, Rep, Precision >::level ( const level< Reference, Rep2, Precision2 > & l )

inlineexplicitconstexpr

Explicit constructor for lossy precision conversions.

Definition at line 261 of file decibel.hpp.

◆ ~level()

template<typename Reference , typename Rep , typename Precision >

electro::level< Reference, Rep, Precision >::~level ( )

default

Member Function Documentation

◆ count()

template<typename Reference , typename Rep , typename Precision >

constexpr rep electro::level< Reference, Rep, Precision >::count ( ) const

inlineconstexpr

Returns the raw offset count, in units of Precision.

Definition at line 271 of file decibel.hpp.

References electro::quantity< Unit, Rep, Precision >::count().

◆ max()

template<typename Reference , typename Rep , typename Precision >

static constexpr level electro::level< Reference, Rep, Precision >::max ( )

inlinestaticconstexprnoexcept

Returns the maximum representable level.

Definition at line 301 of file decibel.hpp.

References electro::level< Reference, Rep, Precision >::level(), and electro::quantity< Unit, Rep, Precision >::max().

◆ min()

template<typename Reference , typename Rep , typename Precision >

static constexpr level electro::level< Reference, Rep, Precision >::min ( )

inlinestaticconstexprnoexcept

Returns the minimum representable level.

Definition at line 298 of file decibel.hpp.

References electro::level< Reference, Rep, Precision >::level(), and electro::quantity< Unit, Rep, Precision >::min().

◆ offset_from_reference()

template<typename Reference , typename Rep , typename Precision >

constexpr offset electro::level< Reference, Rep, Precision >::offset_from_reference ( ) const

inlineconstexpr

Returns the offset from the reference point.

Definition at line 268 of file decibel.hpp.

◆ operator+()

template<typename Reference , typename Rep , typename Precision >

constexpr level electro::level< Reference, Rep, Precision >::operator+ ( ) const

inlineconstexpr

Definition at line 282 of file decibel.hpp.

◆ operator+=()

template<typename Reference , typename Rep , typename Precision >

constexpr level & electro::level< Reference, Rep, Precision >::operator+= ( const offset & o )

inlineconstexpr

Definition at line 284 of file decibel.hpp.

References electro::treat_as_inexact_v.

◆ operator-()

template<typename Reference , typename Rep , typename Precision >

constexpr level electro::level< Reference, Rep, Precision >::operator- ( ) const

inlineconstexpr

Reflects the level about its reference point.

Provided so that negative literals such as -73_dBm parse. Note that std::chrono::time_point offers no such operator; a level is an absolute point, and negating one is only meaningful as "the same magnitude of offset, on the other side of the reference".

Definition at line 281 of file decibel.hpp.

References electro::level< Reference, Rep, Precision >::level().

◆ operator-=()

template<typename Reference , typename Rep , typename Precision >

constexpr level & electro::level< Reference, Rep, Precision >::operator-= ( const offset & o )

inlineconstexpr

Definition at line 289 of file decibel.hpp.

References electro::treat_as_inexact_v.

◆ operator=()

template<typename Reference , typename Rep , typename Precision >

level & electro::level< Reference, Rep, Precision >::operator= ( const level< Reference, Rep, Precision > & )

default

◆ reference_level()

template<typename Reference , typename Rep , typename Precision >

static constexpr level electro::level< Reference, Rep, Precision >::reference_level ( )

inlinestaticconstexprnoexcept

Returns the reference point itself (a 0 dB offset).

Definition at line 295 of file decibel.hpp.

References electro::level< Reference, Rep, Precision >::level(), and electro::quantity< Unit, Rep, Precision >::zero().

The documentation for this class was generated from the following file:

electro/decibel.hpp

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Typedef Documentation

◆ offset

◆ precision

◆ reference

◆ rep

Constructor & Destructor Documentation

◆ level() [1/6]

◆ level() [2/6]

◆ level() [3/6]

◆ level() [4/6]

◆ level() [5/6]

◆ level() [6/6]

◆ ~level()

Member Function Documentation

◆ count()

◆ max()

◆ min()

◆ offset_from_reference()

◆ operator+()

◆ operator+=()

◆ operator-()

◆ operator-=()

◆ operator=()

◆ reference_level()