获得cout的精度 [英] Get precision of cout

问题描述

我可以使用

  cout设置 cout 精度（precision_value）; 
  

如何获取精确值， c $ c> cout 已经？
我在 cout description 。

我遇到的相关问题是如何只改变代码的某些部分的cout精度

 <$ c $ 
 c> // save original cout flags 
 std :: ios_base :: fmtflags coutFlags = cout.flags（）; 
 
 cout.precision（1）; 
 cout.setf（ios :: fixed）; 
 
 // code 
 
 cout.flags（coutFlags）; 
  

但这不行。

解决方案

此功能是重载 。两个重载都返回在调用函数之前设置的精度。 cout.precision（）可能是你想查询的。

要保存并稍后再设置：

  auto old_precision = cout.precision（temp_precision）; 
 // do stuff 
 cout.precision（old_precision）; 
  

I can set precision of cout output using

cout.precision(precision_value);

how can I get the precision value, which is used by cout already? I can't find any other related function in cout description.

The related problem I faced is how can I change cout precision for some part of a code only (so it need to be reset afterwards to exact previous value).

I tryed:

//save original cout flags
std::ios_base::fmtflags coutFlags = cout.flags();

cout.precision(1);
cout.setf(ios::fixed);

 // code

cout.flags(coutFlags);

but this doens't work.

解决方案

The function is overloaded. Both overloads return the precision that was set before the call to the function. cout.precision() may be what you want to query it.

To save it and set it back later:

auto old_precision = cout.precision(temp_precision);
// do stuff
cout.precision(old_precision);

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