Ansgar Burchardt authored 9 years ago and Christoph Grüninger committed 9 years ago

(cherry picked from commit bb04c50d)

This check was added to improve the error message returned when using
MPI without correctly initializing it (e.g. by creating a parallel
grid), see FS#1612 for further information.

[Typetraits][Compatibility] Provide partial backwards compatibility for is_indexable on old GCC versions

Older GCC versions have some nasty bugs related to SFINAE and indexing
with operator[]. This patch adds a configuration check for those
problems and a partial backwards compatibility hack for those older
compilers that is sufficient for our current use case in the VTK
writer.

GCC 4.4, I'm looking at you

is_indexable can be used to test whether a type can be indexed (via
operator[]).

@Markus: too much CMake?! ;-)

There is not need to send message that contain no data. It might even
produce problems on  some implementation. Therfore this patch always
checks the size and simply sets the request to inactive (aka
MPI_REQUEST_NULL) if no data would be send or received.

The patch is to be cherry-picked to master if Christian approves.

we again rethrow the exception, as some information is not available
in the parser routines.

This reverts commit 9281f717.

in order to improve error messages further we introduce a new member
variable prefix_. Sometimes it is important to pass subtrees around.
In this case it is difficult to interpret error messages, as the user
doesn't know in which subtree the problem occured. Now a Parametertree
knows its prefix and can tell it to the user. This way the report
method is simplified and the throws are now more readable.

If an iterator facade (like entity iterators) wants to allow the
embedded implementation to return either an (internally stored)
reference or a temporary object and expose these two behaviors to enable
performance optimizations, operator->() needs special handling: If the
implementation returns a reference, operator->() in the facade can
simply return the address of the referenced object, but if the returned
object is a temporary, we need to capture and store it in a helper
object to make sure it outlives the member access.

This patch adds a little helper function that tansparently handles both
cases.

The ForLoop TMP used to put a number of restrictions on the arguments to
apply(), mainly due to the limited capabilities of C++01 wrt. to
argument forwarding.

But now we have C++11, so we can throw away all that awkward code and
replace it with a single forwarding function that supports arbitrary
numbers of arbitrary combinations of lvalues and rvalues - all hail
variadic templates and perfect forwarding!

If LAPACK is not available, it return 77 indicating skipped test

Like we do for Autotools.
This is only supported for CMake 3.0 or newer. Oder versions ignore
the property and report the test as failed.

g++-4.5 was not tested.
g++-4.6 is ok with lambdas.

These check whether std::call_once() works and provide a helpful error message
if it does not.  They should be used in any code that uses std::call_once().

Call once may not work if one forgets to _link_ with -pthread (or similar
options).  The nasty think about this is that linking still succeeds, so this
can only be detected at run time.  We cannot (in general) run compiled
programs during configure, since we may be cross-compiling, so whatever we get
from configure is at best a guess.

Even if configure detects the necessary flags correctly, there may still be
errors in the build system such that the executable is linked without them.

The reason to provide such a facility is that the bug is quite difficult to
debug when it appears.  The error message is mangled due to a different bug,
and is quite unhelpful anyway.  And then there is the fun with weak symbols...

This specialization was missing and made it impossible to parse bitsets.
The implementation uses the specialization for bool. It was not possible
to reuse the parseRange method, because a bitset doesnt have begin() and end().

While the following is legal c++11

  array<T,n> foo = { t1, t2, ...}

older compilers (namely gcc-4.4) issue a warning on missing braces.

This reverts commit d26e5ed3.
We have to wait until our minimal required compiler is GCC 4.7
or newer.
Thanks to Carsten for the heads-up.

The signature changed in C++11 which we require now.
To get more details see the mailinglost in October 2012.

It should be std::endl.
Courtesy of GCC 5-svn, it refuses to compile these.

GCC warns about it.

While gcc supports them (as extension) runtime sized arrays
are not standard c++. They are not even contained in c++14
but postponed to a later TS.