DeepLearningOpenCpp 2.2.0

DeepLearningOpenCpp NuGet package

As it was pointed out by Michael Nielsen in his book Neural Networks and Deep Learning:

"In many parts of science – especially those parts that deal with simple phenomena – it’s possible to obtain very solid, very reliable evidence for quite general hypotheses. But in neural networks there are large numbers of parameters and hyper-parameters, and extremely complex interactions between them. In such extraordinarily complex systems it’s exceedingly difficult to establish reliable general statements. Understanding neural networks in their full generality is a problem that, like quantum foundations, tests the limits of the human mind."

This project, which was mostly inspired by the book by Michael Nielsen, is pursuing two main goals:

1. provide an open source C++ framework for developing and experimenting with neural network-based algorithms;
2. develop a high performance open source C++ library/NuGet package of machine learning algorithms.

A source-only native NuGet package that ships the headers (.h, .inl) and sources (.cpp) of the DeepLearning project. The package injects them into the consumer's C++ project so the consumer's own compiler / toolset builds the library — eliminating MSVC ABI and STL-version drift concerns inherent to prebuilt static libraries.

• Package id: DeepLearningOpenCpp
• Language standard: C++20 (/std:c++20 /permissive- enforced on consumer)
• Transitive dependency: msgpack-c-cpp-3.1.1-winsoft666 ([1.0.0.2, ))

Installation

In a native C++ project (.vcxproj):

Install-Package DeepLearningOpenCpp

or add to packages.config:

<package id="DeepLearningOpenCpp" version="1.0.0" targetFramework="native" />
<package id="msgpack-c-cpp-3.1.1-winsoft666" version="1.0.0.2" targetFramework="native" />

After NuGet restore, the package will:

1. Add the include root build\native\include\ plus the sub-folder roots include\Math\, include\NeuralNet\, include\Diagnostics\, include\ImageProcessing\ and include\ThirdParty\ to AdditionalIncludeDirectories. The sub-folder entries are required so that bare-name sibling #includes inside the shipped .cpp sources (e.g. #include "LinAlg2d.h" from src\Math\Vector.cpp) resolve without any extra configuration on the consumer side.
2. Unless DeepLearningCompileSources is set to false, add every shipped .cpp to the project's ClCompile items (with <PrecompiledHeader>NotUsing</PrecompiledHeader>).
3. Set <LanguageStandard>stdcpp20 and, unless DeepLearningEnforceConformance is set to false, <ConformanceMode>true</ConformanceMode>.
4. Conditionally append USE_AVX2; and USE_SINGLE_PRECISION; to PreprocessorDefinitions, and set <EnableEnhancedInstructionSet> to AdvancedVectorExtensions2 when AVX2 is enabled.

Opt-out / opt-in properties

All public properties are MSBuild properties; override them in the top-level <PropertyGroup> of your .vcxproj (or in a Directory.Build.props) before the package import is processed:

Example — disable AVX2 and use double:

<PropertyGroup Label="DeepLearningOpenCpp">
  <DeepLearningUseAvx2>false</DeepLearningUseAvx2>
  <DeepLearningUseSinglePrecision>false</DeepLearningUseSinglePrecision>
</PropertyGroup>

Multi-project solutions (header-only consumers)

In a solution where one project (e.g. a static-lib Core project) compiles the DeepLearning sources and other projects (tests, DLL, executables) consume Core transitively, only the Core project should compile the sources. Otherwise the sources are compiled into every consumer and the linker reports LNK2005 / duplicate-symbol errors.

For each header-only consumer, install the package and set:

<PropertyGroup Label="DeepLearningOpenCpp">
  <DeepLearningCompileSources>false</DeepLearningCompileSources>
</PropertyGroup>

This keeps the include directories, defines and language standard active on the consumer (so its own translation units can #include DeepLearning headers) without re-compiling the library.

Migrating TrainingCell from <ProjectReference> to the NuGet package

In TrainingCell\TrainingCell.vcxproj, remove the project reference:

<ProjectReference Include="..\DeepLearning\DeepLearning\DeepLearning.vcxproj">
  <Project>{50160b3b-7ff2-43c0-b650-54332ef4fa75}</Project>
</ProjectReference>

…and add the package to packages.config (or via Install-Package). The git submodule that pulls DeepLearning can then be removed.

If the consuming project manages USE_AVX2 and/or USE_SINGLE_PRECISION on a per-configuration basis (as TrainingCell does), set DeepLearningUseAvx2 / DeepLearningUseSinglePrecision to false so the package doesn't inject them globally.

In every other project in the solution (tests, DLL, console exe) that already transitively links against the static lib, install the package with DeepLearningCompileSources=false so they get the headers but do not re-compile the sources.

Versioning

The package version is inferred from the most recent Git tag of the form v<MAJOR>.<MINOR>.<PATCH> (e.g. v1.0.0 → 1.0.0). The CI workflow publishes to nuget.org only on v* tag pushes; other pushes produce a CI prerelease (<base>-ci.<run_number>) artifact for inspection.

Toolset

The CI runner uses windows-2022 with VCToolsVersion=14.44.35207 pinned. This is informational only — because the package is source-only the consumer's local toolset is what compiles the code.

Troubleshooting

• cl : Command line error D8016 : '/arch:AVX2' and '/arch:...' incompatible Set <DeepLearningUseAvx2>false</DeepLearningUseAvx2> or remove the conflicting /arch: flag from the consumer project.
• LNK2005 / "already defined" errors in a multi-project solution: The shipped .cpp sources are being compiled into more than one project. Pick a single project to compile them and set <DeepLearningCompileSources>false</DeepLearningCompileSources> on the others (see Multi-project solutions above).
• PCH errors on injected .cpp files: ensure the consumer project does not force <PrecompiledHeader>Use</PrecompiledHeader> globally via <ItemDefinitionGroup>. The package sets NotUsing per-file but a later <ItemDefinitionGroup> could override it.
• Missing msgpack headers: confirm the msgpack-c-cpp-3.1.1-winsoft666 transitive dependency restored; check packages\ directory.