feat add toml

3party/toml11/toml/result.hpp

@@ -0,0 +1,717 @@
+//     Copyright Toru Niina 2017.
+// Distributed under the MIT License.
+#ifndef TOML11_RESULT_HPP
+#define TOML11_RESULT_HPP
+#include "traits.hpp"
+#include <type_traits>
+#include <stdexcept>
+#include <utility>
+#include <new>
+#include <string>
+#include <sstream>
+#include <cassert>
+
+namespace toml
+{
+
+template<typename T>
+struct success
+{
+    using value_type = T;
+    value_type value;
+
+    explicit success(const value_type& v)
+        noexcept(std::is_nothrow_copy_constructible<value_type>::value)
+        : value(v)
+    {}
+    explicit success(value_type&& v)
+        noexcept(std::is_nothrow_move_constructible<value_type>::value)
+        : value(std::move(v))
+    {}
+
+    template<typename U>
+    explicit success(U&& v): value(std::forward<U>(v)) {}
+
+    template<typename U>
+    explicit success(const success<U>& v): value(v.value) {}
+    template<typename U>
+    explicit success(success<U>&& v): value(std::move(v.value)) {}
+
+    ~success() = default;
+    success(const success&) = default;
+    success(success&&)      = default;
+    success& operator=(const success&) = default;
+    success& operator=(success&&)      = default;
+};
+
+template<typename T>
+struct failure
+{
+    using value_type = T;
+    value_type value;
+
+    explicit failure(const value_type& v)
+        noexcept(std::is_nothrow_copy_constructible<value_type>::value)
+        : value(v)
+    {}
+    explicit failure(value_type&& v)
+        noexcept(std::is_nothrow_move_constructible<value_type>::value)
+        : value(std::move(v))
+    {}
+
+    template<typename U>
+    explicit failure(U&& v): value(std::forward<U>(v)) {}
+
+    template<typename U>
+    explicit failure(const failure<U>& v): value(v.value) {}
+    template<typename U>
+    explicit failure(failure<U>&& v): value(std::move(v.value)) {}
+
+    ~failure() = default;
+    failure(const failure&) = default;
+    failure(failure&&)      = default;
+    failure& operator=(const failure&) = default;
+    failure& operator=(failure&&)      = default;
+};
+
+template<typename T>
+success<typename std::remove_cv<typename std::remove_reference<T>::type>::type>
+ok(T&& v)
+{
+    return success<
+        typename std::remove_cv<typename std::remove_reference<T>::type>::type
+        >(std::forward<T>(v));
+}
+template<typename T>
+failure<typename std::remove_cv<typename std::remove_reference<T>::type>::type>
+err(T&& v)
+{
+    return failure<
+        typename std::remove_cv<typename std::remove_reference<T>::type>::type
+        >(std::forward<T>(v));
+}
+
+inline success<std::string> ok(const char* literal)
+{
+    return success<std::string>(std::string(literal));
+}
+inline failure<std::string> err(const char* literal)
+{
+    return failure<std::string>(std::string(literal));
+}
+
+
+template<typename T, typename E>
+struct result
+{
+    using value_type = T;
+    using error_type = E;
+    using success_type = success<value_type>;
+    using failure_type = failure<error_type>;
+
+    result(const success_type& s): is_ok_(true)
+    {
+        auto tmp = ::new(std::addressof(this->succ)) success_type(s);
+        assert(tmp == std::addressof(this->succ));
+        (void)tmp;
+    }
+    result(const failure_type& f): is_ok_(false)
+    {
+        auto tmp = ::new(std::addressof(this->fail)) failure_type(f);
+        assert(tmp == std::addressof(this->fail));
+        (void)tmp;
+    }
+    result(success_type&& s): is_ok_(true)
+    {
+        auto tmp = ::new(std::addressof(this->succ)) success_type(std::move(s));
+        assert(tmp == std::addressof(this->succ));
+        (void)tmp;
+    }
+    result(failure_type&& f): is_ok_(false)
+    {
+        auto tmp = ::new(std::addressof(this->fail)) failure_type(std::move(f));
+        assert(tmp == std::addressof(this->fail));
+        (void)tmp;
+    }
+
+    template<typename U>
+    result(const success<U>& s): is_ok_(true)
+    {
+        auto tmp = ::new(std::addressof(this->succ)) success_type(s.value);
+        assert(tmp == std::addressof(this->succ));
+        (void)tmp;
+    }
+    template<typename U>
+    result(const failure<U>& f): is_ok_(false)
+    {
+        auto tmp = ::new(std::addressof(this->fail)) failure_type(f.value);
+        assert(tmp == std::addressof(this->fail));
+        (void)tmp;
+    }
+    template<typename U>
+    result(success<U>&& s): is_ok_(true)
+    {
+        auto tmp = ::new(std::addressof(this->succ)) success_type(std::move(s.value));
+        assert(tmp == std::addressof(this->succ));
+        (void)tmp;
+    }
+    template<typename U>
+    result(failure<U>&& f): is_ok_(false)
+    {
+        auto tmp = ::new(std::addressof(this->fail)) failure_type(std::move(f.value));
+        assert(tmp == std::addressof(this->fail));
+        (void)tmp;
+    }
+
+    result& operator=(const success_type& s)
+    {
+        this->cleanup();
+        this->is_ok_ = true;
+        auto tmp = ::new(std::addressof(this->succ)) success_type(s);
+        assert(tmp == std::addressof(this->succ));
+        (void)tmp;
+        return *this;
+    }
+    result& operator=(const failure_type& f)
+    {
+        this->cleanup();
+        this->is_ok_ = false;
+        auto tmp = ::new(std::addressof(this->fail)) failure_type(f);
+        assert(tmp == std::addressof(this->fail));
+        (void)tmp;
+        return *this;
+    }
+    result& operator=(success_type&& s)
+    {
+        this->cleanup();
+        this->is_ok_ = true;
+        auto tmp = ::new(std::addressof(this->succ)) success_type(std::move(s));
+        assert(tmp == std::addressof(this->succ));
+        (void)tmp;
+        return *this;
+    }
+    result& operator=(failure_type&& f)
+    {
+        this->cleanup();
+        this->is_ok_ = false;
+        auto tmp = ::new(std::addressof(this->fail)) failure_type(std::move(f));
+        assert(tmp == std::addressof(this->fail));
+        (void)tmp;
+        return *this;
+    }
+
+    template<typename U>
+    result& operator=(const success<U>& s)
+    {
+        this->cleanup();
+        this->is_ok_ = true;
+        auto tmp = ::new(std::addressof(this->succ)) success_type(s.value);
+        assert(tmp == std::addressof(this->succ));
+        (void)tmp;
+        return *this;
+    }
+    template<typename U>
+    result& operator=(const failure<U>& f)
+    {
+        this->cleanup();
+        this->is_ok_ = false;
+        auto tmp = ::new(std::addressof(this->fail)) failure_type(f.value);
+        assert(tmp == std::addressof(this->fail));
+        (void)tmp;
+        return *this;
+    }
+    template<typename U>
+    result& operator=(success<U>&& s)
+    {
+        this->cleanup();
+        this->is_ok_ = true;
+        auto tmp = ::new(std::addressof(this->succ)) success_type(std::move(s.value));
+        assert(tmp == std::addressof(this->succ));
+        (void)tmp;
+        return *this;
+    }
+    template<typename U>
+    result& operator=(failure<U>&& f)
+    {
+        this->cleanup();
+        this->is_ok_ = false;
+        auto tmp = ::new(std::addressof(this->fail)) failure_type(std::move(f.value));
+        assert(tmp == std::addressof(this->fail));
+        (void)tmp;
+        return *this;
+    }
+
+    ~result() noexcept {this->cleanup();}
+
+    result(const result& other): is_ok_(other.is_ok())
+    {
+        if(other.is_ok())
+        {
+            auto tmp = ::new(std::addressof(this->succ)) success_type(other.as_ok());
+            assert(tmp == std::addressof(this->succ));
+            (void)tmp;
+        }
+        else
+        {
+            auto tmp = ::new(std::addressof(this->fail)) failure_type(other.as_err());
+            assert(tmp == std::addressof(this->fail));
+            (void)tmp;
+        }
+    }
+    result(result&& other): is_ok_(other.is_ok())
+    {
+        if(other.is_ok())
+        {
+            auto tmp = ::new(std::addressof(this->succ)) success_type(std::move(other.as_ok()));
+            assert(tmp == std::addressof(this->succ));
+            (void)tmp;
+        }
+        else
+        {
+            auto tmp = ::new(std::addressof(this->fail)) failure_type(std::move(other.as_err()));
+            assert(tmp == std::addressof(this->fail));
+            (void)tmp;
+        }
+    }
+
+    template<typename U, typename F>
+    result(const result<U, F>& other): is_ok_(other.is_ok())
+    {
+        if(other.is_ok())
+        {
+            auto tmp = ::new(std::addressof(this->succ)) success_type(other.as_ok());
+            assert(tmp == std::addressof(this->succ));
+            (void)tmp;
+        }
+        else
+        {
+            auto tmp = ::new(std::addressof(this->fail)) failure_type(other.as_err());
+            assert(tmp == std::addressof(this->fail));
+            (void)tmp;
+        }
+    }
+    template<typename U, typename F>
+    result(result<U, F>&& other): is_ok_(other.is_ok())
+    {
+        if(other.is_ok())
+        {
+            auto tmp = ::new(std::addressof(this->succ)) success_type(std::move(other.as_ok()));
+            assert(tmp == std::addressof(this->succ));
+            (void)tmp;
+        }
+        else
+        {
+            auto tmp = ::new(std::addressof(this->fail)) failure_type(std::move(other.as_err()));
+            assert(tmp == std::addressof(this->fail));
+            (void)tmp;
+        }
+    }
+
+    result& operator=(const result& other)
+    {
+        this->cleanup();
+        if(other.is_ok())
+        {
+            auto tmp = ::new(std::addressof(this->succ)) success_type(other.as_ok());
+            assert(tmp == std::addressof(this->succ));
+            (void)tmp;
+        }
+        else
+        {
+            auto tmp = ::new(std::addressof(this->fail)) failure_type(other.as_err());
+            assert(tmp == std::addressof(this->fail));
+            (void)tmp;
+        }
+        is_ok_ = other.is_ok();
+        return *this;
+    }
+    result& operator=(result&& other)
+    {
+        this->cleanup();
+        if(other.is_ok())
+        {
+            auto tmp = ::new(std::addressof(this->succ)) success_type(std::move(other.as_ok()));
+            assert(tmp == std::addressof(this->succ));
+            (void)tmp;
+        }
+        else
+        {
+            auto tmp = ::new(std::addressof(this->fail)) failure_type(std::move(other.as_err()));
+            assert(tmp == std::addressof(this->fail));
+            (void)tmp;
+        }
+        is_ok_ = other.is_ok();
+        return *this;
+    }
+
+    template<typename U, typename F>
+    result& operator=(const result<U, F>& other)
+    {
+        this->cleanup();
+        if(other.is_ok())
+        {
+            auto tmp = ::new(std::addressof(this->succ)) success_type(other.as_ok());
+            assert(tmp == std::addressof(this->succ));
+            (void)tmp;
+        }
+        else
+        {
+            auto tmp = ::new(std::addressof(this->fail)) failure_type(other.as_err());
+            assert(tmp == std::addressof(this->fail));
+            (void)tmp;
+        }
+        is_ok_ = other.is_ok();
+        return *this;
+    }
+    template<typename U, typename F>
+    result& operator=(result<U, F>&& other)
+    {
+        this->cleanup();
+        if(other.is_ok())
+        {
+            auto tmp = ::new(std::addressof(this->succ)) success_type(std::move(other.as_ok()));
+            assert(tmp == std::addressof(this->succ));
+            (void)tmp;
+        }
+        else
+        {
+            auto tmp = ::new(std::addressof(this->fail)) failure_type(std::move(other.as_err()));
+            assert(tmp == std::addressof(this->fail));
+            (void)tmp;
+        }
+        is_ok_ = other.is_ok();
+        return *this;
+    }
+
+    bool is_ok()  const noexcept {return is_ok_;}
+    bool is_err() const noexcept {return !is_ok_;}
+
+    operator bool() const noexcept {return is_ok_;}
+
+    value_type&       unwrap() &
+    {
+        if(is_err())
+        {
+            throw std::runtime_error("toml::result: bad unwrap: " +
+                                     format_error(this->as_err()));
+        }
+        return this->succ.value;
+    }
+    value_type const& unwrap() const&
+    {
+        if(is_err())
+        {
+            throw std::runtime_error("toml::result: bad unwrap: " +
+                                     format_error(this->as_err()));
+        }
+        return this->succ.value;
+    }
+    value_type&&      unwrap() &&
+    {
+        if(is_err())
+        {
+            throw std::runtime_error("toml::result: bad unwrap: " +
+                                     format_error(this->as_err()));
+        }
+        return std::move(this->succ.value);
+    }
+
+    value_type&       unwrap_or(value_type& opt) &
+    {
+        if(is_err()) {return opt;}
+        return this->succ.value;
+    }
+    value_type const& unwrap_or(value_type const& opt) const&
+    {
+        if(is_err()) {return opt;}
+        return this->succ.value;
+    }
+    value_type        unwrap_or(value_type opt) &&
+    {
+        if(is_err()) {return opt;}
+        return this->succ.value;
+    }
+
+    error_type&       unwrap_err() &
+    {
+        if(is_ok()) {throw std::runtime_error("toml::result: bad unwrap_err");}
+        return this->fail.value;
+    }
+    error_type const& unwrap_err() const&
+    {
+        if(is_ok()) {throw std::runtime_error("toml::result: bad unwrap_err");}
+        return this->fail.value;
+    }
+    error_type&&      unwrap_err() &&
+    {
+        if(is_ok()) {throw std::runtime_error("toml::result: bad unwrap_err");}
+        return std::move(this->fail.value);
+    }
+
+    value_type&       as_ok() &      noexcept {return this->succ.value;}
+    value_type const& as_ok() const& noexcept {return this->succ.value;}
+    value_type&&      as_ok() &&     noexcept {return std::move(this->succ.value);}
+
+    error_type&       as_err() &      noexcept {return this->fail.value;}
+    error_type const& as_err() const& noexcept {return this->fail.value;}
+    error_type&&      as_err() &&     noexcept {return std::move(this->fail.value);}
+
+
+    // prerequisities
+    // F: T -> U
+    // retval: result<U, E>
+    template<typename F>
+    result<detail::return_type_of_t<F, value_type&>, error_type>
+    map(F&& f) &
+    {
+        if(this->is_ok()){return ok(f(this->as_ok()));}
+        return err(this->as_err());
+    }
+    template<typename F>
+    result<detail::return_type_of_t<F, value_type const&>, error_type>
+    map(F&& f) const&
+    {
+        if(this->is_ok()){return ok(f(this->as_ok()));}
+        return err(this->as_err());
+    }
+    template<typename F>
+    result<detail::return_type_of_t<F, value_type &&>, error_type>
+    map(F&& f) &&
+    {
+        if(this->is_ok()){return ok(f(std::move(this->as_ok())));}
+        return err(std::move(this->as_err()));
+    }
+
+    // prerequisities
+    // F: E -> F
+    // retval: result<T, F>
+    template<typename F>
+    result<value_type, detail::return_type_of_t<F, error_type&>>
+    map_err(F&& f) &
+    {
+        if(this->is_err()){return err(f(this->as_err()));}
+        return ok(this->as_ok());
+    }
+    template<typename F>
+    result<value_type, detail::return_type_of_t<F, error_type const&>>
+    map_err(F&& f) const&
+    {
+        if(this->is_err()){return err(f(this->as_err()));}
+        return ok(this->as_ok());
+    }
+    template<typename F>
+    result<value_type, detail::return_type_of_t<F, error_type&&>>
+    map_err(F&& f) &&
+    {
+        if(this->is_err()){return err(f(std::move(this->as_err())));}
+        return ok(std::move(this->as_ok()));
+    }
+
+    // prerequisities
+    // F: T -> U
+    // retval: U
+    template<typename F, typename U>
+    detail::return_type_of_t<F, value_type&>
+    map_or_else(F&& f, U&& opt) &
+    {
+        if(this->is_err()){return std::forward<U>(opt);}
+        return f(this->as_ok());
+    }
+    template<typename F, typename U>
+    detail::return_type_of_t<F, value_type const&>
+    map_or_else(F&& f, U&& opt) const&
+    {
+        if(this->is_err()){return std::forward<U>(opt);}
+        return f(this->as_ok());
+    }
+    template<typename F, typename U>
+    detail::return_type_of_t<F, value_type&&>
+    map_or_else(F&& f, U&& opt) &&
+    {
+        if(this->is_err()){return std::forward<U>(opt);}
+        return f(std::move(this->as_ok()));
+    }
+
+    // prerequisities
+    // F: E -> U
+    // retval: U
+    template<typename F, typename U>
+    detail::return_type_of_t<F, error_type&>
+    map_err_or_else(F&& f, U&& opt) &
+    {
+        if(this->is_ok()){return std::forward<U>(opt);}
+        return f(this->as_err());
+    }
+    template<typename F, typename U>
+    detail::return_type_of_t<F, error_type const&>
+    map_err_or_else(F&& f, U&& opt) const&
+    {
+        if(this->is_ok()){return std::forward<U>(opt);}
+        return f(this->as_err());
+    }
+    template<typename F, typename U>
+    detail::return_type_of_t<F, error_type&&>
+    map_err_or_else(F&& f, U&& opt) &&
+    {
+        if(this->is_ok()){return std::forward<U>(opt);}
+        return f(std::move(this->as_err()));
+    }
+
+    // prerequisities:
+    // F: func T -> U
+    // toml::err(error_type) should be convertible to U.
+    // normally, type U is another result<S, F> and E is convertible to F
+    template<typename F>
+    detail::return_type_of_t<F, value_type&>
+    and_then(F&& f) &
+    {
+        if(this->is_ok()){return f(this->as_ok());}
+        return err(this->as_err());
+    }
+    template<typename F>
+    detail::return_type_of_t<F, value_type const&>
+    and_then(F&& f) const&
+    {
+        if(this->is_ok()){return f(this->as_ok());}
+        return err(this->as_err());
+    }
+    template<typename F>
+    detail::return_type_of_t<F, value_type&&>
+    and_then(F&& f) &&
+    {
+        if(this->is_ok()){return f(std::move(this->as_ok()));}
+        return err(std::move(this->as_err()));
+    }
+
+    // prerequisities:
+    // F: func E -> U
+    // toml::ok(value_type) should be convertible to U.
+    // normally, type U is another result<S, F> and T is convertible to S
+    template<typename F>
+    detail::return_type_of_t<F, error_type&>
+    or_else(F&& f) &
+    {
+        if(this->is_err()){return f(this->as_err());}
+        return ok(this->as_ok());
+    }
+    template<typename F>
+    detail::return_type_of_t<F, error_type const&>
+    or_else(F&& f) const&
+    {
+        if(this->is_err()){return f(this->as_err());}
+        return ok(this->as_ok());
+    }
+    template<typename F>
+    detail::return_type_of_t<F, error_type&&>
+    or_else(F&& f) &&
+    {
+        if(this->is_err()){return f(std::move(this->as_err()));}
+        return ok(std::move(this->as_ok()));
+    }
+
+    // if *this is error, returns *this. otherwise, returns other.
+    result and_other(const result& other) const&
+    {
+        return this->is_err() ? *this : other;
+    }
+    result and_other(result&& other) &&
+    {
+        return this->is_err() ? std::move(*this) : std::move(other);
+    }
+
+    // if *this is okay, returns *this. otherwise, returns other.
+    result or_other(const result& other) const&
+    {
+        return this->is_ok() ? *this : other;
+    }
+    result or_other(result&& other) &&
+    {
+        return this->is_ok() ? std::move(*this) : std::move(other);
+    }
+
+    void swap(result<T, E>& other)
+    {
+        result<T, E> tmp(std::move(*this));
+        *this = std::move(other);
+        other = std::move(tmp);
+        return ;
+    }
+
+  private:
+
+    static std::string format_error(std::exception const& excpt)
+    {
+        return std::string(excpt.what());
+    }
+    template<typename U, typename std::enable_if<!std::is_base_of<
+        std::exception, U>::value, std::nullptr_t>::type = nullptr>
+    static std::string format_error(U const& others)
+    {
+        std::ostringstream oss; oss << others;
+        return oss.str();
+    }
+
+    void cleanup() noexcept
+    {
+        if(this->is_ok_) {this->succ.~success_type();}
+        else             {this->fail.~failure_type();}
+        return;
+    }
+
+  private:
+
+    bool      is_ok_;
+    union
+    {
+        success_type succ;
+        failure_type fail;
+    };
+};
+
+template<typename T, typename E>
+void swap(result<T, E>& lhs, result<T, E>& rhs)
+{
+    lhs.swap(rhs);
+    return;
+}
+
+// this might be confusing because it eagerly evaluated, while in the other
+// cases operator && and || are short-circuited.
+//
+// template<typename T, typename E>
+// inline result<T, E>
+// operator&&(const result<T, E>& lhs, const result<T, E>& rhs) noexcept
+// {
+//     return lhs.is_ok() ? rhs : lhs;
+// }
+//
+// template<typename T, typename E>
+// inline result<T, E>
+// operator||(const result<T, E>& lhs, const result<T, E>& rhs) noexcept
+// {
+//     return lhs.is_ok() ? lhs : rhs;
+// }
+
+// ----------------------------------------------------------------------------
+// re-use result<T, E> as a optional<T> with none_t
+
+namespace detail
+{
+struct none_t {};
+inline bool operator==(const none_t&, const none_t&) noexcept {return true;}
+inline bool operator!=(const none_t&, const none_t&) noexcept {return false;}
+inline bool operator< (const none_t&, const none_t&) noexcept {return false;}
+inline bool operator<=(const none_t&, const none_t&) noexcept {return true;}
+inline bool operator> (const none_t&, const none_t&) noexcept {return false;}
+inline bool operator>=(const none_t&, const none_t&) noexcept {return true;}
+template<typename charT, typename traitsT>
+std::basic_ostream<charT, traitsT>&
+operator<<(std::basic_ostream<charT, traitsT>& os, const none_t&)
+{
+    os << "none";
+    return os;
+}
+inline failure<none_t> none() noexcept {return failure<none_t>{none_t{}};}
+} // detail
+} // toml11
+#endif// TOML11_RESULT_H