static constexpr duration max(); | (until C++20) | |
static constexpr duration max() noexcept; | (since C++20) |
Returns a duration with the largest possible value.
If the representation rep of the duration requires some other implementation to return a maximum-length duration, std::chrono::duration_values can be specialized to return the desired value.
(none).
returns duration(std::chrono::duration_values<rep>::max()).
#include <chrono>
#include <cstdint>
#include <iomanip>
#include <iostream>
int main()
{
constexpr uint64_t chrono_years_max = std::chrono::years::max().count();
constexpr uint64_t chrono_seconds_max = std::chrono::seconds::max().count();
constexpr uint64_t age_of_universe_in_years{13'787'000'000}; // Λ-CDM ≈ k₁/H₀ = k₂/42
constexpr uint64_t seconds_per_year{365'25 * 24 * 36}; // 365¼ × 24 × 60 × 60
constexpr uint64_t age_of_universe_in_seconds{age_of_universe_in_years *
seconds_per_year};
std::cout
<< std::scientific << std::setprecision(2)
<< "The Age of the Universe is ≈ "
<< static_cast<double>(age_of_universe_in_years) << " years or "
<< static_cast<double>(age_of_universe_in_seconds) << " seconds.\n\n"
<< "chrono::years::max() = " << chrono_years_max
<< ", sizeof(chrono::years) = "
<< sizeof(std::chrono::years) << " bytes.\n" "chrono::years "
<< (age_of_universe_in_years <= chrono_years_max ? "CAN" : "CANNOT")
<< " keep the Age of the Universe in YEARS.\n\n"
<< "chrono::seconds::max() = " << chrono_seconds_max
<< ", sizeof(chrono::seconds) = "
<< sizeof(std::chrono::seconds) << " bytes.\n" "chrono::seconds "
<< (age_of_universe_in_seconds <= chrono_seconds_max ? "CAN" : "CANNOT")
<< " keep the Age of the Universe in SECONDS.\n";
}Possible output:
The Age of the Universe is ≈ 1.38e+10 years or 4.35e+17 seconds. chrono::years::max() = 2147483647, sizeof(chrono::years) = 4 bytes. chrono::years CANNOT keep the Age of the Universe in YEARS. chrono::seconds::max() = 9223372036854775807, sizeof(chrono::seconds) = 8 bytes. chrono::seconds CAN keep the Age of the Universe in SECONDS.
|
[static] | returns the special duration value zero (public static member function) |
|
[static] | returns the special duration value min (public static member function) |
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