Analitza's use of C99 variable-length arrays

[Aleix Pol]

On Tue, Jul 1, 2014 at 5:03 AM, Nicolás Alvarez <nicolas.alvarez at gmail.com>
wrote:

> Hi peeps,
>
> In analitza/commands/blockmatrixcommands.cpp, there is a variable-length
> array:
>
> const int firstVectorSize = firstVector->size();
> int blockpattern[firstVectorSize];
>
> This is a new feature in C99. The GCC manual says: "Variable-length
> automatic arrays are allowed in ISO C99, and as an extension GCC
> accepts them in C90 mode and in C++."
>
> MSVC doesn't support VLAs, at least not in C++ mode. And given the
> above quote, it seems it's non-portable to use it in C++ anyway, so
> (this time :P) we can't blame it on MSVC not being standards-compliant
> or something.
>
> I replaced it with this to make it compile:
> std::unique_ptr<int[]> blockpattern(new int[firstVectorSize]);
>
> But I don't know if this is acceptable (can I use C++11 in analitza?).
> ##c++ told me to just use
> std::vector<int> blockpattern(firstVectorSize, 0);
>
> which is a reasonable option, but it feels weird to use a std::vector
> for something that won't be resized.
>
> I welcome thoughts from someone who actually knows the Analitza code :)
>
>
Hi,
Wouldn't that fix the issue?

Aleix

diff --git analitza/commands/blockmatrixcommands.cpp
analitza/commands/blockmatrixcommands.cpp
index 6ff20ef..568fbde 100644
--- analitza/commands/blockmatrixcommands.cpp
+++ analitza/commands/blockmatrixcommands.cpp
@@ -62,7 +62,7 @@ Expression BlockMatrixCommand::operator()(const QList<
Analitza::Expression >& a
  bool isCorrect = true; // this flag tells if is ok to build the block
matrix
  int nrows = 0;
  int ncols = 0;
- int blockpattern[firstVectorSize]; // if vectors(matrixrow) this tells
the row(column) pattern
+ std::vector<int> blockpattern(firstVectorSize, 0); // if
vectors(matrixrow) this tells the row(column) pattern

  const int blocklength = isVector? firstBlock->columnCount() :
firstBlock->rowCount();
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