[#mp_units-utility-constrained-operator_dec-0d4]
= xref:mp_units.adoc[mp_units]::xref:mp_units/utility.adoc[utility]::xref:mp_units/utility/constrained.adoc[constrained]::operator‐‐
:relfileprefix: ../../../
:mrdocs:

Decrement operators

== Synopses

Declared in `<mp‐units/utility/constrained.h>`

Pre‐decrements the wrapped value.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
constexpr
xref:mp_units/utility/constrained.adoc[constrained]&
xref:mp_units/utility/constrained/operator_dec-0d8.adoc[operator‐‐]()
requires requires(T& v) {
      { ‐‐v } ‐> std::same_as<T&>;
    };
----

[.small]#xref:mp_units/utility/constrained/operator_dec-0d8.adoc[_» more..._]#

Post‐decrements the wrapped value.


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
constexpr
xref:mp_units/utility/constrained.adoc[constrained<decltype(std::declval<T&>()‐‐), ErrorPolicy>]
xref:mp_units/utility/constrained/operator_dec-09.adoc[operator‐‐](int tag);
----

[.small]#xref:mp_units/utility/constrained/operator_dec-09.adoc[_» more..._]#

== Return Value

* a reference to `*this`, after decrementing
* the value before decrementing, wrapped in `constrained`

== Parameters

[cols="1,4"]
|===
| Name| Description
| *tag*
| unused; disambiguates this postfix overload from the prefix `operator‐‐()`
|===


[.small]#Created with https://www.mrdocs.com[MrDocs]#