NEWS.md

In cpp11: A C++11 Interface for R's C Interface

cpp11 0.5.0

R non-API related changes

• Removed usage of the following R non-API functions:

• SETLENGTH()

• SET_TRUELENGTH()

• SET_GROWABLE_BIT()

These functions were used as part of the efficient growable vectors that cpp11 offered, i.e. what happens under the hood when you use push_back(). The removal of these non-API functions means that cpp11 writable vectors that have been pushed to with push_back() will likely force 1 extra allocation when the conversion from cpp11::writable::r_vector<T> to SEXP occurs (typically when you return a result back to R). This does not affect the performance of push_back() itself, and in general these growable vectors are still quite efficient (#362).

• The environment class no longer uses the non-API function Rf_findVarInFrame3() (#367).

• The exists() method now uses the new R_existsVarInFrame() function.

• The SEXP conversion operator now uses the new R_getVar() function. Note that this is stricter than Rf_findVarInFrame3() in 3 ways. The object must exist in the environment (i.e. R_UnboundValue is no longer returned), the object cannot be R_MissingArg, and if the object was a promise, that promise is now evaluated. We have backported this new strictness to older versions of R as well.

New features

• cpp11::writable::r_vector<T>::proxy now implements copy assignment. Practically this means that x[i] = y[i] now works when both x and y are writable vectors (#300, #339).

• New writable::data_frame constructor that also takes the number of rows as input. This accounts for the edge case where the input list has 0 columns but you'd still like to specify a known number of rows (#272).

• std::max_element() can now be used with writable vectors (#334).

• Read only r_vectors now have a move constructor and move assignment operator (#365).

Improvements and fixes

• Repeated assignment to a cpp11::writable::strings vector through either x[i] = elt or x.push_back(elt) is now more performant, at the tradeoff of slightly less safety (as long as elt is actually a CHARSXP and i is within bounds, there is no chance of failure, which are the same kind of invariants placed on the other vector types) (#378).

• Constructors for writable vectors from initializer_list<named_arg> now check that named_arg contains a length 1 object of the correct type, and throws either a cpp11::type_error or std::length_error if that is not the case (#382).

• cpp11::package now errors if given a package name that hasn't been loaded yet. Previously it would cause R to hang indefinitely (#317).

• cpp11::function now protects its underlying function, for maximum safety (#294).

• cpp11::writable::r_vector<T>::iterator no longer implicitly deletes its copy assignment operator (#360).

• Added the missing implementation for x.at("name") for read only vectors (#370).

• Fixed an issue with the writable::matrix copy constructor where the underlying SEXP should have been copied but was not. It is now consistent with the behavior of the equivalent writable::r_vector copy constructor.

• Fixed a memory leak with the cpp11::writable::r_vector move assignment operator (#338).

• Fixed an issue where writable vectors were being protected twice (#365).

• The approach for the protection list managed by cpp11 has been tweaked slightly. In 0.4.6, we changed to an approach that creates one protection list per compilation unit, but we now believe we've found an approach that is guaranteed by the C++ standard to create one protection list per package, which makes slightly more sense and still has all the benefits of the reduced maintanence burden mentioned in the 0.4.6 news bullet (#364).

A side effect of this new approach is that the preserved object exposed through protect.hpp no longer exists. We don't believe that anyone was using this. This also means you should no longer see "unused variable" warnings about preserved (#249).

Breaking changes

• R >=3.6.0 is now required. This is in line with (and even goes beyond) the tidyverse standard of supporting the previous 5 minor releases of R.

• Implicit conversion from sexp to bool, size_t, and double has been marked as deprecated and will be removed in the next version of cpp11. The 3 packages that were using this have been notified and sent PRs. The recommended approach is to instead use cpp11::as_cpp<T>, which performs type and length checking, making it much safer to use.

• Dropped support for gcc 4.8, mainly an issue for extremely old CentOS 7 systems which used that as their default compiler. As of June 2024, CentOS 7 is past its vendor end of support date and therefore also out of scope for Posit at this time (#359).

cpp11 0.4.7

• Internal changes requested by CRAN to fix invalid format string tokens (@paleolimbot, #345).

cpp11 0.4.6

• R >=3.5.0 is now required to use cpp11. This is in line with (and even goes beyond) the tidyverse standard of supporting the previous 5 minor releases of R. It also ensures that R_UnwindProtect() is available to avoid C++ memory leaks (#332).

• cpp11::preserved.release_all() has been removed. This was intended to support expert developers on R <3.5.0 when cpp11 used a global protection list. Since cpp11 no longer uses a global protection list and requires R

  =3.5.0, it is no longer needed. As far as we can tell, no package was actively using this (#332).

• cpp11 now creates one protection list per compilation unit, rather than one global protection list shared across compilation units and across packages. This greatly reduces the complexity of managing the protection list state and should make it easier to make changes to the protection list structure in the future without breaking packages compiled with older versions of cpp11 (#330).

• Nested calls to cpp11::unwind_protect() are no longer supported or encouraged. Previously, this was something that could be done for performance improvements, but ultimately this feature has proven to cause more problems than it is worth and is very hard to use safely. For more information, see the new vignette("FAQ") section titled "Should I call cpp11::unwind_protect() manually?" (#327).

• The features and bug fixes from cpp11 0.4.4 have been added back in.

cpp11 0.4.5

• On 2023-07-20, cpp11 was temporarily rolled back to 0.4.3 manually by CRAN due to a bug in 0.4.4 which we could not immediately fix due to the cpp11 maintainer being on vacation.

cpp11 0.4.4

• Davis Vaughan is now the maintainer.

• as_doubles() and as_integers() now propagate missing values correctly (#265, #319).

• Fixed a performance issue related to nested unwind_protect() calls (#298).

• Minor performance improvements to the cpp11 protect code. (@kevinushey)

• cpp_register() gains an argument extension= governing the file extension of the src/cpp11 file. By default it's .cpp, but .cc is now supported as well (#292, @MichaelChirico)

cpp11 0.4.3

• Modernized the GitHub Actions workflows and updated some internal tests to better align with changes in those workflows and the latest version of R (#279).

• cpp_source() errors on non-existent file (#261).

• cpp_register() is quiet by default when R is non interactive (#289).

• updated test to adapt to changes in R 4.2.1 (#290).

cpp11 0.4.2

• Romain François is now the maintainer.

cpp11 0.4.1

• Fix crash related to unwind protect optimization (#244)

cpp11 0.4.0

New Features

• New opt-in message formatting with the {fmt} C++ library for cpp11::messages() cpp11::stop() and cpp11::warning(). Set the CPP11_USE_FMT macro to use this feature in your package. (@sbearrows, #169, #208)
• New as_double() and as_integer() methods to coerce integers to doubles and doubles to integers to doubles (@sbearrows, #46)
• cpp11::matrix iterators can now be used either row-wise or column-wise (the default) depending on the user's choice (@alyst, #229)

Improvements and fixes

• Read-only matrix accessors are now marked const (#234)
• writable::r_vector default constructors now return a 0 length vector when converted to SEXP (#166)
• Read-only r_vector constructors now disallow implicit construction with named arguments (#237)
• Read-only r_vector.attr() methods now return const objects, so it is a compile time error to try to assign to them (#237)
• Fixed + and += operators of r_vector::[const_]iterator to conform the iterators concept: += updates the iterator, and + returns the updated copy, while keeping the original unchanged (@alyst, #231)
• Remove undefined behavior when constructing global cpp11::sexps (#224)
• Removed redundant .Call calls in cpp11.cpp file (@sbearrows, #170)
• Error messages now output original file name rather than the temporary file name (@sbearrows, #194)
• cpp_register() now includes attribute_visible in the init function, so packages compiled with C_VISIBILITY will find the init function.
• Fixed bug when running cpp_source() on the same file more than once (@sbearrows, #202)
• Allow cpp11 decorators of the form cpp11::linking_to (@sbearrows, #193)
• Removed internal instances of cpp11::stop() and replaced with C++ exceptions (@sbearrows, #203)
• Names of named lists are now resized along with the list elements (@sbearrows, #206)

cpp11 0.3.1

• Fix stringop-truncation warning from generated wrapping code.

cpp11 0.3.0

New functions and features

• New x.empty() method to check if a vector is empty (@sbearrows, #182)
• New x.named() method to check if a vector is named (@sbearrows, #186)
• New na() free function to return the NA sentinels for R objects (@sbearrows, #179)

Major fixes

• Memory no longer inadvertently leaks when move constructing vectors (#173)

Minor improvements and fixes

• Incorrectly formatted cpp11 decorators now output a more informative error message (@sbearrows, #127)
• Generated registration code now uses C collation to avoid spurious changes from tools::package_native_routine_registration_skeleton() (@sbearrows, #171)
• Makevars files which include filenames now handle spaces in paths properly (@klmr, #160)

cpp11 0.2.7

• Fix a transient memory leak for functions that return values from cpp11::unwind_protect() and cpp11::safe (#154)
• cpp_source() now gets an argument dir to allow customized temporary directory to store generated source files. It makes it easier to debug C++ source files in non-package project via source mapping. (@renkun-ken, #156)

cpp11 0.2.6

• cpp_register() now uses symbols exclusively in the .Call() interface. This allows it to be more robust in interactive use with the pkgload package.

cpp11 0.2.5

• cpp_source() gains a cxx_std argument to control which C++ standard is used. This allows you to use code from C++14 and later standards with cpp_source(). (#100)
• The cpp11 knitr engine now allows you to set the cxx_std chunk option to control the C++ standard used.
• cpp_source() now has much more informative error messages when compilation fails (#125, #139)
• cpp_source() now uses a unique name for the DLL, so works when run multiple times on the same source file on Windows (#143)
• writable::list_of<T> now supports modification of vectors as intended (#131).
• Errors when running tools::package_native_routine_registration_skeleton() are no longer swallowed (#134)
• cpp_source() can now accept a source file called cpp11.cpp (#133)
• named_arg now explicitly protect their values, avoiding protection issues when using large inputs. tidyverse/readr#1145
• r_string(std::string) now uses Rf_mkCharLenCE() instead of Rf_mkChar(), which avoids the performance cost of checking the string length.
• Writable vector classes now properly set their lengths as intended when being copied to a read only class (#128).

cpp11 0.2.4

• The preserve list is now more robust to invalid values, such as when the XPtr has no address or if non-xptr's are stored in the option. This fixes errors when reloading packages using cpp11 and RStudio's session restores.
• The preserve list is now more robust to invalid values, such as null pointers when the XPtr is serialized. This situation occurs during 'Install and Restart' in RStudio (#121)

cpp11 0.2.3

• r_vector::const_iterator::operator* is now a const method (#113, @bkietz, @xhochy)
• The preserve list is now stored in an XPtr, rather than an environment, to avoid issues when serializing the preserve environment, which happens implicitly when RStudio or RStudio Cloud saves all options when resuming a session (#116)

cpp11 0.2.2

• r_bool added as an adapter between bool and Rboolean values (#57, @bkietz)

• data_frame() objects now have the number of rows correctly set as real length, not the reserved length (#91)

• Fixed potential memory leak in cpp11::writable classes.

cpp11 0.2.1

• Ensures backwards compatibility with code generation from cpp11 0.1.0 (#88)

• push_back() now works more consistently with named arguments (#86)

cpp11 0.2.0

New features

• cpp11 is now able to compile on gcc 4.8.5 (#69, @bkietz)

• cpp_source(), cpp_function() and cpp_eval() now support [[cpp11::linking_to()]] syntax to link to third party packages with C++ headers. (#48)

Minor improvements and fixes

• as_cpp<E>() now works with enumeration types (#52, @bkietz)

• as_cpp<int>() and as_cpp<double>() now implicitly coerce between all 3 types of single NA values (#53).

• list::const_iterator::operator*() added so iterators could be used on list objects (#60, @romainfrancois)

• safe[] can now work with functions that return any type (#70, @bkietz)

• The END_CPP macro now includes a catch(...) block to catch all C++ exceptions that do not inherit from std::exception (#47).

• Improve consistency of inserting NA values in r_string objects (#45)

• Added a NEWS.md file to track changes to the package.

cpp11 0.1.0

• Initial release

cpp11 documentation built on Sept. 11, 2024, 9:31 p.m.