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lines 15-85 of file: include/cppad/core/cppad_assert.hpp
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{xrst_begin cppad_assert}
{xrst_spell
   msg
}

CppAD Assertions During Execution
#################################

Syntax
******
| ``CPPAD_ASSERT_KNOWN`` ( *exp* , *msg* )
| ``CPPAD_ASSERT_UNKNOWN`` ( *exp* )

Purpose
*******
These CppAD macros are used to detect and report errors.
They are documented here because they correspond to the C++
source code that the error is reported at.

NDEBUG
******
If the preprocessor symbol
:ref:`Faq@Speed@NDEBUG` is defined,
these macros do nothing; i.e., they are optimized out.

Restriction
***********
The CppAD user should not uses these macros.
You can however write your own macros that do not begin with ``CPPAD``
and that call the :ref:`CppAD error handler<ErrorHandler-name>` .

Known
*****
The ``CPPAD_ASSERT_KNOWN`` macro is used to check for an error
with a known cause.
For example, many CppAD routines uses these macros
to make sure their arguments conform to their specifications.

Unknown
*******
The ``CPPAD_ASSERT_UNKNOWN`` macro is used to check that the
CppAD internal data structures conform as expected.
If this is not the case, CppAD does not know why the error has
occurred; for example, the user may have written past the end
of an allocated array.

Exp
***
The argument *exp* is a C++ source code expression
that results in a ``bool`` value that should be true.
If it is false, an error has occurred.
This expression may be execute any number of times
(including zero times) so it must have not side effects.

Msg
***
The argument *msg* has prototype

   ``const char`` * *msg*

and contains a ``'\0'`` terminated character string.
This string is a description of the error
corresponding to *exp* being false.

Error Handler
*************
These macros use the
:ref:`CppAD error handler<ErrorHandler-name>` to report errors.
This error handler can be replaced by the user.

{xrst_end cppad_assert}