[#293]:svarga:build, vendor self-contained header-only Boost uBLAS (1.89) so examples build without system Boost

Author: steven-varga

examples/CMakeLists.txt

@@ -222,19 +222,11 @@ else()
     endif()
 endif()
 
-# ublas headers are vendored but rely on system Boost config/compiler headers
-find_path(H5CPP_BOOST_CONFIG_INCLUDE_EX NAMES boost/config.hpp)
-if(H5CPP_BOOST_CONFIG_INCLUDE_EX)
-    message( "-- Vendored: ublas added to examples" )
-    # examples/attributes/attributes.cpp uses the boost/* layout
-    # (#include <boost/numeric/ublas/matrix.hpp>); the vendored libublas only
-    # exposes the numeric/* layout, so propagate the system/vcpkg Boost include
-    # dir through libublas for any target that links it.
-    target_include_directories(libublas INTERFACE ${H5CPP_BOOST_CONFIG_INCLUDE_EX})
-    add_h5cpp_example(ublas linalg/ublas.cpp LIBRARIES libublas)
-else()
-    message("-- Boost config headers not found — ublas example disabled")
-endif()
+# uBLAS is fully vendored (header-only closure under thirdparty/ublas, #293) —
+# libublas resolves <boost/numeric/ublas/...> standalone, so no system Boost is
+# required and the example always builds.
+message("-- Vendored: ublas added to examples")
+add_h5cpp_example(ublas linalg/ublas.cpp LIBRARIES libublas)
 
 # ------------------------------------------------------------------------------
 # Sparse linalg examples (CSC group layout, scipy/Julia interop)

test/examples/CMakeLists.txt

@@ -41,18 +41,11 @@ add_example_test(test_arma_io     LIBRARIES libarmadillo)
 add_example_test(test_blaze_io    LIBRARIES libblaze)
 add_example_test(test_dlib_io     LIBRARIES libdlib)
 
-# ublas v1.74 uses std::allocator::construct which was removed in C++20.
-# Skip the ublas test under C++20 builds.
-if(CMAKE_CXX_STANDARD LESS 20)
-    find_path(H5CPP_BOOST_CONFIG_INCLUDE NAMES boost/config.hpp)
-    if(H5CPP_BOOST_CONFIG_INCLUDE)
-        add_example_test(test_ublas_io LIBRARIES libublas)
-    else()
-        message(STATUS "Boost config headers not found — skipping test_ublas_io")
-    endif()
-else()
-    message(STATUS "C++20 build — skipping test_ublas_io (ublas v1.74 requires std::allocator::construct, removed in C++20)")
-endif()
+# uBLAS is fully vendored (header-only, #293). The bundled 1.89 is C++20-clean
+# (the std::allocator::construct removal that forced v1.74 to be skipped under
+# C++20 is long fixed), and libublas resolves <boost/...> without system Boost,
+# so the test builds unconditionally.
+add_example_test(test_ublas_io LIBRARIES libublas)
 
 add_example_test(test_blitz_io    LIBRARIES libblitz)
 

thirdparty/ublas/CMakeLists.txt

@@ -8,6 +8,10 @@ set(name ublas)
 set(libname lib${name})
 project(${libname} LANGUAGES CXX)
 
-set(current_version_dir "v1.74.0")
+set(current_version_dir "v1.89.0")
 add_library(${libname} INTERFACE)
+# The vendored tree is a bcp-extracted, header-only closure laid out under a
+# `boost/` prefix, so <boost/numeric/ublas/...> resolves entirely from here —
+# no system Boost, no compiled libs, no BLAS/LAPACK. uBLAS ships its own (slow)
+# fallbacks; BLAS bindings are a separate opt-in we do not use.
 target_include_directories(${libname} INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/${current_version_dir})