`mp_units::si::invoke_with_prefixed`¶

Calls an invocable with a quantity scaled to an automatically selected SI prefix

Synopsis¶

Declared in <mp-units/systems/si/prefix_utils.h>

template<Quantity Q, std::invocable<Q> Func, PrefixableUnit U, auto Character = quantity_character{}>
  requires RepresentationOf<typename Q::rep, Character> && treat_as_floating_point<typename Q::rep> &&
           requires(Q::rep v) {
             requires requires { abs(v); } || requires { std::abs(v); };
             requires requires { log10(v); } || requires { std::log10(v); };
             requires requires { floor(v); } || requires { std::floor(v); };
           }
constexpr decltype(auto) invoke_with_prefixed(Func func, Q q, U u, prefix_range range = prefix_range::engineering,
                                              int min_integral_digits = 1);

Description¶

Selects an SI prefix such that the integral part of the quantity's numerical value has at least min_integral_digits digits.

NOTE

For min_integral_digits=1

engineering mode: values displayed in range [1.0, 999.999...]
full mode: values displayed in range [1.0, 9.999...]

Return Value¶

The result of calling func with the scaled quantity

Template Parameters¶

Name	Description
Q	Quantity type
Func	Invocable type that accepts a quantity
U	PrefixableUnit type

Parameters¶

Name	Description
func	Invocable to call with the scaled quantity
q	Quantity to scale
u	Unit to use as the base for prefix selection
range	Prefix selection mode: - `prefix_range::engineering` selects only powers of 1000 (kilo, mega, milli, etc.), resulting in values in range [1.0, 1000)] - `prefix_range::full` selects all SI prefixes including deca, hecto, deci, centi, resulting in values values in [1.0, 10) within the milli–kilo range, [1.0, 1000) elsewhere]]
min_integral_digits	Minimum number of digits in the integral part (default: 1)

mp_units::si::invoke_with_prefixed¶