問題描述

所以我有一個(gè)隨機(jī)對象:

So i have a Random object:

typedef unsigned int uint32;

class Random {
public:
    Random() = default;
    Random(std::mt19937::result_type seed) : eng(seed) {}

private:
    uint32 DrawNumber();
    std::mt19937 eng{std::random_device{}()};
    std::uniform_int_distribution<uint32> uniform_dist{0, UINT32_MAX};
};

uint32 Random::DrawNumber()
{
    return uniform_dist(eng);
}

我可以改變(通過另一個(gè)函數(shù)或其他方式)分布上限的最佳方法是什么?

What's the best way I can vary (through another function or otherwise) the upper bound of of the distribution?

(也愿意接受其他風(fēng)格問題的建議)

(also willing to take advice on other style issues)

推薦答案

分發(fā)對象是輕量級(jí)的.當(dāng)您需要隨機(jī)數(shù)時(shí)，只需構(gòu)建一個(gè)新的分布.我在游戲引擎中使用這種方法，經(jīng)過基準(zhǔn)測試后，它可以與使用舊的 rand() 相媲美.

Distribution objects are lightweight. Simply construct a new distribution when you need a random number. I use this approach in a game engine, and, after benchmarking, it's comparable to using good old rand().

此外，我在 GoingNative 2013 直播中詢問了如何改變分發(fā)范圍，標(biāo)準(zhǔn)委員會(huì)成員 Stephen T. Lavavej 建議簡單地創(chuàng)建新分發(fā)，因?yàn)樗粦?yīng)該是表演問題.

Also, I've asked how to vary the range of distribution on GoingNative 2013 live stream, and Stephen T. Lavavej, a member of the standard committee, suggested to simply create new distributions, as it shouldn't be a performance issue.

以下是我將如何編寫您的代碼:

Here's how I would write your code:

using uint32 = unsigned int;

class Random {
public:
    Random() = default;
    Random(std::mt19937::result_type seed) : eng(seed) {}
    uint32 DrawNumber(uint32 min, uint32 max);

private:        
    std::mt19937 eng{std::random_device{}()};
};

uint32 Random::DrawNumber(uint32 min, uint32 max)
{
    return std::uniform_int_distribution<uint32>{min, max}(eng);
}

這篇關(guān)于改變uniform_int_distribution的范圍的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網(wǎng)！