OpenSystemsDevelopment / qpdf

…n `QPDFPageDocumentHelper`, `QPDFPageObjectHelper` and `QPDFPageLabelDocumentHelper`.

…jectHelper`: replace `getArrayNItems` with `size`, simplify array traversal, and centralize `empty` checks for improved clarity and efficiency.

…`warn`, streamline condition handling.

Converted multiple occurrences of `count()` to `contains()` throughout the codebase where the goal was to check key existence in containers. This improves code readability and aligns with modern C++ practices, particularly with C++20, making the intent more explicit and potentially aiding performance.

Simplified code by removing redundant `this` qualifiers where they are not essential, improving readability and alignment with coding standards. No changes were made to functionality.

Replace data member oh with accessors.

Remove redundant overloads from QPDFObjGen::set.

This improves indentation of long strings. This commit also fixes some
trailing whitespace in ChangeLog.

Add copy_if_fallback and explain how it differs from copy_if_shared.

Also, inline method and add optional parameter error_msg.

Remove any ambiguity around whether old or new value is being
returned.

Use 'QPDFObjGen const&' instead of 'int, int' in signature.

Also, revert inlining of unparse and operator << from commit 4c6640c in
order to avoid exposing QUtil.

I decided these were confusing and inconsistent with how JSON works.
They muddle the API rather than improving it.

Change .clang-format and commit automated changes from a fresh run of
format-code

* Merge overloaded functions by adding default values
* Remove non-const methods that are identical to const methods

(patrepl and cleanpatch are my own utilities)

patrepl s/PointerHolder/std::shared_ptr/g {include,libqpdf}/qpdf/*.hh
patrepl s/PointerHolder/std::shared_ptr/g libqpdf/*.cc
patrepl s/make_pointer_holder/std::make_shared/g libqpdf/*.cc
patrepl s/make_array_pointer_holder/QUtil::make_shared_array/g libqpdf/*.cc
patrepl s,qpdf/std::shared_ptr,qpdf/PointerHolder, **/*.cc **/*.hh
git restore include/qpdf/PointerHolder.hh
cleanpatch
./format-code

Run this:

for i in  **/*.cc **/*.c **/*.h **/*.hh; do
  clang-format < $i >| $i.new && mv $i.new $i
done

This comment expands all tabs using an 8-character tab-width. You
should ignore this commit when using git blame or use git blame -w.

In the early days, I used to use tabs where possible for indentation,
since emacs did this automatically. In recent years, I have switched
to only using spaces, which means qpdf source code has been a mixture
of spaces and tabs. I have avoided cleaning this up because of not
wanting gratuitous whitespaces change to cloud the output of git
blame, but I changed my mind after discussing with users who view qpdf
source code in editors/IDEs that have other tab widths by default and
in light of the fact that I am planning to start applying automatic
code formatting soon.