[round.style]

# 17 Language support library [[support]](./#support)

## 17.3 Implementation properties [[support.limits]](support.limits#round.style)

### 17.3.4 Enum float_round_style [round.style]

[🔗](#lib:float_round_style)

namespace std {enum float_round_style { round_indeterminate = -1,
 round_toward_zero = 0,
 round_to_nearest = 1,
 round_toward_infinity = 2,
 round_toward_neg_infinity = 3};}

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/support.tex#L968)

The rounding mode for floating-point arithmetic is characterized by the
values:

- [(1.1)](#1.1)

round_indeterminate if the rounding style is indeterminable

- [(1.2)](#1.2)

round_toward_zero if the rounding style is toward zero

- [(1.3)](#1.3)

round_to_nearest if the rounding style is to the nearest representable value

- [(1.4)](#1.4)

round_toward_infinity if the rounding style is toward infinity

- [(1.5)](#1.5)

round_toward_neg_infinity if the rounding style is toward negative infinity