celeritas::Constant Class Reference

Full-precision floating point constant with automatic precision demotion. More...

#include <Constant.hh>

Public Types
Type aliases
using	real_type = double

Public Member Functions
CELER_CONSTEXPR_FUNCTION	Constant (real_type v)
	Explicitly construct from a full-precision value.
CELER_CONSTEXPR_FUNCTION real_type	value () const
	Access the value explicitly.
CELER_CONSTEXPR_FUNCTION	operator float () const
	Explicit conversion of stored value.
CELER_CONSTEXPR_FUNCTION	operator double () const
	Explicit access to stored value.

Detailed Description

Full-precision floating point constant with automatic precision demotion.

We want two behaviors from constants in Celeritas:

1. They don't accidentally promote runtime arithmetic from single to double precision when compiling at a lower precision. This incurs a substantial performance penalty on GPU.
2. We can use their full double-precision values when we need to: either in templated code or when interacting with other libraries. (For example, float(pi) > pi which can lead to errors in Geant4.)

This class stores a full-precision (double) value as its "real type" and defines explicit conversion operators that allow it to automatically convert to a lower-precision or real-precision type.

Operations with a floating point value returns a value of that precision (performed at that precision level); operations with integers return a full-precision Constant; and operations with Constants return a Constant.

---

The documentation for this class was generated from the following file:

• Constant.hh