NarrowCast.h

//  trax track library
//  AD 2022 
//
//  "the resolution of all the fruitless searches"
//
//                              Peter Gabriel
//
//
// Copyright (c) 2025 Trend Redaktions- und Verlagsgesellschaft mbH
// Copyright (c) 2019 Marc-Michael Horstmann
//
// Permission is hereby granted to any person obtaining a copy of this software 
// and associated source code (the "Software"), to use, view, and study the 
// Software for personal or internal business purposes, subject to the following 
// conditions:
//
// 1. Redistribution, modification, sublicensing, or commercial use of the 
// Software is NOT permitted without prior written consent from the copyright 
// holder.
//
// 2. The Software is provided "AS IS", without warranty of any kind, express 
// or implied.
//
// 3. All copies of the Software must retain this license notice.
//
// For further information, please contact: horstmann.marc@trendverlag.de
 
#pragma once
 
#include <memory>
#include <stdexcept>
 
namespace common{

    template<typename Target, typename Source>
    struct NarrowCast_Imp {
        static inline Target narrow_cast( Source v ) {
            const Target r = static_cast<Target>(v);
            if( static_cast<Source>(r) != v )
                throw std::runtime_error("narrow_cast<>() failed");
 
            return r;
        }
    };
 
    template<typename SameType>
    struct NarrowCast_Imp<SameType, SameType> {
        static inline SameType narrow_cast( SameType v ) noexcept {
            return v;
        }
    };

    template<typename Target, typename Source>
    inline Target narrow_cast( Source v ){
        return NarrowCast_Imp<Target, Source>::narrow_cast(v);
    }
 
 
    template <typename Target, typename Source>
    std::unique_ptr<Target> dynamic_unique_cast(std::unique_ptr<Source>&& source) {
        if( auto* casted = dynamic_cast<Target*>(source.get()) ) {
            source.release();                       
            return std::unique_ptr<Target>( casted );
        }
 
        return nullptr;
    }
 
}