公共成員函式
<random>
(1) | void seed(); |
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(2) | void seed (result_type val); |
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(3) | template <class Sseq>void seed (Sseq& q); |
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Seed base engine (為基礎引擎設定種子)
透過呼叫其 base,重新初始化 base 引擎的狀態seedmember function with the same argument (if any). (同名引數(如果存在)成員函式,重新初始化其狀態。)
引數
- val
- 一個播種值。此值傳遞給 base 引擎的建構函式。
result_type是一個成員型別,定義為由 base 生成的元素型別的別名。
- q
- 一個種子序列物件,例如seed_seq型別的物件。
Sseq應為具有generate成員函式的種子序列類。
示例
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// discard_block_engine::seed example
#include <iostream>
#include <chrono>
#include <random>
int main ()
{
typedef std::chrono::high_resolution_clock myclock;
myclock::time_point beginning = myclock::now();
// obtain a seed from a user string:
std::string str;
std::cout << "Please, enter a seed: ";
std::getline(std::cin,str);
std::seed_seq seed1 (str.begin(),str.end());
// obtain a seed from the timer
myclock::duration d = myclock::now() - beginning;
unsigned seed2 = d.count();
// ranlux24 is a standard instantitation of discard_block_engine:
std::ranlux24 generator (seed1);
std::cout << "Your seed produced: " << generator() << std::endl;
generator.seed (seed2);
std::cout << "A time seed produced: " << generator() << std::endl;
return 0;
}
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可能的輸出
Please, enter a seed: Cooper
Your seed produced: 14845138
A time seed produced: 12807810
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