60 lines
1.9 KiB
C++
Executable File
60 lines
1.9 KiB
C++
Executable File
#pragma once
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#include <iostream>
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#include <limits>
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#include <ostream>
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#include <string>
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#include <functional>
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constexpr auto all = std::numeric_limits<std::streamsize>::max();
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namespace math
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{
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template<auto lb, typeof(lb) ub> [[maybe_unused]]
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constexpr auto is_between(typeof(lb) x) -> bool { return (ub > x) && (x > lb); }
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template<auto lb> [[maybe_unused]]
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constexpr auto is_larger(typeof(lb) x) -> bool { return (x > lb); }
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template<auto ub> [[maybe_unused]]
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constexpr auto is_smaller(typeof(ub) x) -> bool { return (ub > x); }
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template<typename T> [[maybe_unused]]
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auto numerical_suffix(T value) -> std::string
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{
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std::string suffixes[4] = {"th", "st", "nd", "rd"};
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value %= 100;
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if (math::is_between<11,13>(value))
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return "th";
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value %= 10;
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if (math::is_larger<3>(value))
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return "th";
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return suffixes[value % 4];
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}
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}
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struct ip_validator { bool operator()(const std::string& addr) const { return net::getaddrinfo(addr, "0") != nullptr; }};
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template<typename T> [[maybe_unused]]
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T get_input(const std::string& prompt, const std::string& on_error, std::function<bool(T)> validator) noexcept
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{
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T user_input{};
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try
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{
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while (true)
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{
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printf("%s", prompt.c_str());
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std::cin >> user_input;
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if (std::cin.fail() || !validator(user_input))
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{
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std::cout << on_error << std::endl;
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std::cin.clear();
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std::cin.ignore(all, '\n');
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continue;
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}
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break;
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}
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return user_input;
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}
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catch (std::exception&) { return user_input; } /* This should not happen ..... cin/cout are not configured to throw...*/
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}
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struct always_true_validator { template<typename T> bool operator()(T) const { return true; }};
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template<typename T> [[maybe_unused]]
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T get_input(const std::string& prompt) { return get_input<T>(prompt, "", always_true_validator()); } |