lines 726-825 of file: lib/cplusplus/a_double.cpp

{xrst_begin a_double_cond_assign}


AD Conditional Assignment
#########################

Syntax
******
| *target*\ ``.cond_assign`` ( *cop* , *left* , *right* , *if_true* , *if_false* )

Purpose
*******
The code

| |tab| ``if`` ( *left* *cop* *right* )
| |tab| |tab| *target* = *if_true*
| |tab| ``else``
| |tab| |tab| *target* = *if_false*

records either the true or false case depending on the value
of *left* and *right* ; see :ref:`cpp_fun_ctor-name`.
If *left* or *right* is a
:ref:`variable<a_double_property@variable>`,
it may be desirable to switch between *if_true* and *if_false*
depending of the value of the independent variable during
calls to order zero :ref:`cpp_fun_forward-name`.
The ``cond_assign`` does this.

target
******
This object has c++ prototype

| |tab| ``a_double&`` *target*

cop
***
This argument has c++ prototype

| |tab| ``const char *cop``

The comparison is

| |tab| *left* *cop* *right*

where *cop* is one of the following:

.. csv-table::
   :widths: 10, 10

   *cop* ,
   ``<`` , less than
   ``<=`` , less than or equal
   ``==`` , equal
   ``>=`` , greater than or equal
   ``>`` , greater than

left
****
This argument has c++ prototype

| |tab| ``const a_double&`` *left*

It specifies the left operand in the comparison.

right
*****
This argument has c++ prototype

| |tab| ``const a_double&`` *right*

It specifies the right operand in the comparison.

if_true
*******
This argument has c++ prototype

| |tab| ``const a_double&`` *if_true*

It specifies the value assigned to *ad* if the result
of the comparison is true.

if_false
********
This argument has c++ prototype

| |tab| ``const a_double&`` *if_false*

It specifies the value assigned to *ad* if the result
of the comparison is false.

{xrst_toc_hidden
   example/cplusplus/a_double_cond_assign_xam.cpp
   example/python/core/a_double_cond_assign_xam.py
}
Example
*******
:ref:`c++<a_double_cond_assign_xam.cpp-name>`,
:ref:`python<a_double_cond_assign_xam.py-name>`.

{xrst_end a_double_cond_assign}