Two data types used in function definition to_string(long double _Val)

Question

How to understand expression below:

inline string to_string(long double _Val)

{   // convert long double to string
char _Buf[_MAX_EXP_DIG + _MAX_SIG_DIG + 64];

_CSTD sprintf_s(_Buf, sizeof (_Buf), "%Lg", _Val);
return (string(_Buf));
}

Why two data types is used in parameter definition? Is this decried in c++ standard?

that's 1 type - called `long double`. – Daniel A. White Sep 17 '15 at 12:43 — Daniel A. White, Sep 17 '15 at 12:43
https://en.wikipedia.org/wiki/Long_double – Daniel A. White Sep 17 '15 at 12:43 — Daniel A. White, Sep 17 '15 at 12:43

score 0 · Answer 1 · edited May 23 '17 at 12:03

0

That is the actual type. It is called long double. You can read up on it at wikipeida: https://en.wikipedia.org/wiki/Long_double

You can read more here: long double vs double

edited May 23 '17 at 12:03

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answered Sep 17 '15 at 12:44

Daniel A. White

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score 0 · Answer 2 · answered Sep 17 '15 at 12:44

It's a single data type:

long double - extended precision floating point type. Does not necessarily map to types mandated by IEEE-754. Usually 80-bit x87 floating point type on x86 and x86-64 architectures.

Source: http://en.cppreference.com/w/cpp/language/types

Two data types used in function definition to_string(long double _Val)

2 Answers2