### 28.2 Floating-Point Type Specifications ¶

The standard library header file `float.h` defines a number of constants that describe the platform’s implementation of floating-point types `float`, `double` and `long double`. They include:

`FLT_MIN`
`DBL_MIN`
`LDBL_MIN`

  Defines the minimum normalized positive floating-point values that can be represented with the type.

`FLT_HAS_SUBNORM`
`DBL_HAS_SUBNORM`
`LDBL_HAS_SUBNORM`

  Defines if the floating-point type supports subnormal (or “denormalized”) numbers or not (see subnormal numbers).

`FLT_TRUE_MIN`
`DBL_TRUE_MIN`
`LDBL_TRUE_MIN`

  Defines the minimum positive values (including subnormal values) that can be represented with the type.

`FLT_MAX`
`DBL_MAX`
`LDBL_MAX`

  Defines the largest values that can be represented with the type.

`FLT_DECIMAL_DIG`
`DBL_DECIMAL_DIG`
`LDBL_DECIMAL_DIG`

  Defines the number of decimal digits `n` such that any floating-point number that can be represented in the type can be rounded to a floating-point number with `n` decimal digits, and back again, without losing any precision of the value.