bbldc_basicdaterangedaycountadapter

Detailed Description

Outline

• Purpose
• Classes
• Description
  • Usage
    • Example 1: Adapting bbldc::BasicIsma30360

Purpose

Provide a parameterized day-count convention implementation.

Classes

• bbldc::BasicDateRangeDayCountAdapter: bbldc::DateRangeDayCount adapter

Description

This component provides a parameterized (template) implementation, bbldc::BasicDateRangeDayCountAdapter, of the bbldc::DateRangeDayCount protocol. The template argument can be any type supporting the following two class methods.

int daysDiff(const bdlt::Date& beginDate, const bdlt::Date& endDate);
 
double yearsDiff(const bdlt::Date& beginDate, const bdlt::Date& endDate);

The template class bbldc::BasicDateRangeDayCountAdapter provides convenient support for run-time polymorphic choice of day-count conventions (via conventional use of a base-class pointer or reference) without having to implement each derived type explicitly. In this sense, bbldc::BasicDateRangeDayCountAdapter adapts the various concrete "basic" day-count convention classes (e.g., bbldc::BasicIsma30360) to a run-time binding mechanism.

The bbldc::DateRangeDayCount protocol requires two methods, firstDate and lastDate, that define a date range for which calculations are valid, to reflect the valid range of, say, a calendar required for the computations. For "basic" day-count implementations, the valid date range is identical to the range of bdlt::Date.

Usage

This section illustrates intended use of this component.

Example 1: Adapting bbldc::BasicIsma30360

This example shows the procedure for using bbldc::BasicDateRangeDayCountAdapter to adapt the bbldc::BasicIsma30360 day-count convention to the bbldc::DateRangeDayCount protocol, and then the use of the day-count methods. First, we define an instance of the adapted day-count convention and obtain a reference to the bbldc::DateRangeDayCount:

const bbldc::BasicDateRangeDayCountAdapter<bbldc::BasicIsma30360> myDcc =
             bbldc::BasicDateRangeDayCountAdapter<bbldc::BasicIsma30360>();
 
const bbldc::DateRangeDayCount& dcc = myDcc;

Then, create two bdlt::Date variables, d1 and d2, with which to use the day-count convention methods:

const bdlt::Date d1(2003, 10, 18);
const bdlt::Date d2(2003, 12, 31);

Now, use the base-class reference to compute the day count between the two dates:

const int daysDiff = dcc.daysDiff(d1, d2);
assert(72 == daysDiff);

Finally, use the base-class reference to compute the year fraction between the two dates:

const double yearsDiff = dcc.yearsDiff(d1, d2);
// Need fuzzy comparison since 'yearsDiff' is a 'double'.
assert(0.1999 < yearsDiff && 0.2001 > yearsDiff);