xlnt supports reading, editing, and writing various spreadsheet formats and features.

Supported Formats

• Excel-style Workbook: Full Read, Edit, and Write support.
• LibreOffice-style Workbook: Full Read, Edit, and Write support.
• Numbers-style Workbook: Full Read, Edit, and Write support.
• Encrypted Workbooks: Read and Edit support for Excel 2007-2010 and Excel 2013-2016 formats (Write is not supported).

Key Supported Features

• Data & Values: Numeric cell values, Inline string cell values, Shared string cell values, and Shared string text run formatting (e.g., varied fonts within a single cell).
• Formatting: Cell styles, cell formats, alignment, borders, fills, fonts, number formats, and protection (e.g., hiding formulas).
• Metadata & Layout: Document properties, page margins, comments, themes, and XLSX thumbnails.

Unsupported Features

Currently, xlnt does not support Excel Binary (.xlsb), Macro-Enabled (.xlsm, .xltm), Hyperlinks, Formulas (evaluation or values), Charts, Tables, Pivot Tables, or Embedded Content (images).

xlnt uses the pimpl idiom (pointer to implementation) for its core data structures. This design choice allows most major objects to be passed and stored by value rather than requiring the use of pointers or references.

When you copy a core object, you are copying a lightweight wrapper that holds an opaque pointer to the actual data stored within the primary workbook implementation. Methods called on these wrapper objects dereference the pointer to manipulate the underlying data directly.

Because of this model, the following types can be safely passed around and stored by value:

• xlnt::workbook
• xlnt::worksheet
• xlnt::cell
• xlnt::format
• xlnt::style

#include <iostream>
#include <xlnt/xlnt.hpp>

void set_cell(xlnt::cell cell, int value)
{
    cell.value(value);
}

xlnt::workbook create_wb()
{
    xlnt::workbook wb;
    auto ws = wb.active_sheet();
    set_cell(wb.cell("A1"), 2);
    return wb;
}

int main()
{
    auto wb = create_wb();
    // Note: The example in the source contains a likely typo: wb.value<int>() 
    // In practice, you would access a cell value, e.g., wb.cell("A1").value<int>()
    std::cout << wb.value<int>() << std::endl;
    return 0;    
}

Beyond core binding capabilities, pybind11 offers several advanced features:

• Python Compatibility: Supports Python 2.7, 3.x, and PyPy (PyPy2.7 >= 5.7) via an implementation-agnostic interface.
• Performance: Uses C++11 move constructors/assignment for efficient data transfer. It can also use C++14 features (relaxed constexpr and return value deduction) to precompute signatures and reduce binary size.
• NumPy Integration: Supports Python's buffer protocols for fast conversion between C++ matrix classes (like Eigen) and NumPy without expensive copies. It can also automatically vectorize functions to apply them to NumPy array arguments.
• Lambda Support: Can bind C++11 lambda functions with captured variables (the capture data is stored in the resulting Python function object).
• Serialization: C++ types can be pickled and unpickled like regular Python objects.
• Ease of Use: Everything is contained in a few header files; no additional libraries need to be linked. Binaries are significantly smaller than Boost.Python equivalents.

To compile xlnt on Ubuntu 16.04, you must ensure you are using at least gcc 6.2.0. Standard APT repositories may only provide older versions (like gcc 5.4.0), which will cause compilation errors such as workbook.cpp error 1502:31 'extended_property' is not a class, namespace or enumeration.

Follow these steps to update the compiler and install xlnt:

1. Install dependencies and update compiler:

   sudo apt-get update
   sudo apt-get upgrade
   sudo apt-get install cmake
   sudo apt-get install zlibc

Add PPA for newer GCC versions

sudo add-apt-repository ppa:ubuntu-toolchain-r/test sudo apt update sudo apt-get upgrade sudo apt-get install gcc-6 g++-6

Set environment variables to use GCC 6

export CC=/usr/bin/gcc-6
export CXX=/usr/bin/g++-6

2. **Clone and build xlnt:**
   ```bash
git clone https://github.com/tfussell/xlnt.git xlnt --recurse-submodules
cd xlnt
cmake .
make -j 2
sudo make install

3. Update shared library links:

   sudo ldconfig