1 files changed, 337 insertions, 0 deletions
diff --git a/src/arrow/r/inst/include/cpp11/as.hpp b/src/arrow/r/inst/include/cpp11/as.hpp
new file mode 100644
index 000000000..dd9641a16
--- /dev/null
+++ b/src/arrow/r/inst/include/cpp11/as.hpp
@@ -0,0 +1,337 @@
+// cpp11 version: 0.3.1.1
+// vendored on: 2021-08-11
+#pragma once
+
+#include <cmath>             // for modf
+#include <initializer_list>  // for initializer_list
+#include <memory>            // for std::shared_ptr, std::weak_ptr, std::unique_ptr
+#include <string>            // for string, basic_string
+#include <type_traits>       // for decay, enable_if, is_same, is_convertible
+
+#include "cpp11/R.hpp"        // for SEXP, SEXPREC, Rf_xlength, R_xlen_t
+#include "cpp11/protect.hpp"  // for stop, protect, safe, protect::function
+
+namespace cpp11 {
+
+template <bool C, typename R = void>
+using enable_if_t = typename std::enable_if<C, R>::type;
+
+template <typename T>
+using decay_t = typename std::decay<T>::type;
+
+template <typename T>
+struct is_smart_ptr : std::false_type {};
+
+template <typename T>
+struct is_smart_ptr<std::shared_ptr<T>> : std::true_type {};
+
+template <typename T>
+struct is_smart_ptr<std::unique_ptr<T>> : std::true_type {};
+
+template <typename T>
+struct is_smart_ptr<std::weak_ptr<T>> : std::true_type {};
+
+template <typename T, typename R = void>
+using enable_if_constructible_from_sexp =
+    enable_if_t<!is_smart_ptr<T>::value &&  // workaround for gcc 4.8
+                    std::is_class<T>::value && std::is_constructible<T, SEXP>::value,
+                R>;
+
+template <typename T, typename R = void>
+using enable_if_is_sexp = enable_if_t<std::is_same<T, SEXP>::value, R>;
+
+template <typename T, typename R = void>
+using enable_if_convertible_to_sexp = enable_if_t<std::is_convertible<T, SEXP>::value, R>;
+
+template <typename T, typename R = void>
+using disable_if_convertible_to_sexp =
+    enable_if_t<!std::is_convertible<T, SEXP>::value, R>;
+
+template <typename T, typename R = void>
+using enable_if_integral =
+    enable_if_t<std::is_integral<T>::value && !std::is_same<T, bool>::value &&
+                    !std::is_same<T, char>::value,
+                R>;
+
+template <typename T, typename R = void>
+using enable_if_floating_point =
+    typename std::enable_if<std::is_floating_point<T>::value, R>::type;
+
+template <typename E, typename R = void>
+using enable_if_enum = enable_if_t<std::is_enum<E>::value, R>;
+
+template <typename T, typename R = void>
+using enable_if_bool = enable_if_t<std::is_same<T, bool>::value, R>;
+
+template <typename T, typename R = void>
+using enable_if_char = enable_if_t<std::is_same<T, char>::value, R>;
+
+template <typename T, typename R = void>
+using enable_if_std_string = enable_if_t<std::is_same<T, std::string>::value, R>;
+
+template <typename T, typename R = void>
+using enable_if_c_string = enable_if_t<std::is_same<T, const char*>::value, R>;
+
+// https://stackoverflow.com/a/1521682/2055486
+//
+inline bool is_convertable_without_loss_to_integer(double value) {
+  double int_part;
+  return std::modf(value, &int_part) == 0.0;
+}
+
+template <typename T>
+enable_if_constructible_from_sexp<T, T> as_cpp(SEXP from) {
+  return T(from);
+}
+
+template <typename T>
+enable_if_is_sexp<T, T> as_cpp(SEXP from) {
+  return from;
+}
+
+template <typename T>
+enable_if_integral<T, T> as_cpp(SEXP from) {
+  if (Rf_isInteger(from)) {
+    if (Rf_xlength(from) == 1) {
+      return INTEGER_ELT(from, 0);
+    }
+  } else if (Rf_isReal(from)) {
+    if (Rf_xlength(from) == 1) {
+      if (ISNA(REAL_ELT(from, 0))) {
+        return NA_INTEGER;
+      }
+      double value = REAL_ELT(from, 0);
+      if (is_convertable_without_loss_to_integer(value)) {
+        return value;
+      }
+    }
+  } else if (Rf_isLogical(from)) {
+    if (Rf_xlength(from) == 1) {
+      if (LOGICAL_ELT(from, 0) == NA_LOGICAL) {
+        return NA_INTEGER;
+      }
+    }
+  }
+
+  stop("Expected single integer value");
+}
+
+template <typename E>
+enable_if_enum<E, E> as_cpp(SEXP from) {
+  if (Rf_isInteger(from)) {
+    using underlying_type = typename std::underlying_type<E>::type;
+    using int_type = typename std::conditional<std::is_same<char, underlying_type>::value,
+                                               int,  // as_cpp<char> would trigger
+                                                     // undesired string conversions
+                                               underlying_type>::type;
+    return static_cast<E>(as_cpp<int_type>(from));
+  }
+
+  stop("Expected single integer value");
+}
+
+template <typename T>
+enable_if_bool<T, T> as_cpp(SEXP from) {
+  if (Rf_isLogical(from)) {
+    if (Rf_xlength(from) == 1) {
+      return LOGICAL_ELT(from, 0) == 1;
+    }
+  }
+
+  stop("Expected single logical value");
+}
+
+template <typename T>
+enable_if_floating_point<T, T> as_cpp(SEXP from) {
+  if (Rf_isReal(from)) {
+    if (Rf_xlength(from) == 1) {
+      return REAL_ELT(from, 0);
+    }
+  }
+  // All 32 bit integers can be coerced to doubles, so we just convert them.
+  if (Rf_isInteger(from)) {
+    if (Rf_xlength(from) == 1) {
+      if (INTEGER_ELT(from, 0) == NA_INTEGER) {
+        return NA_REAL;
+      }
+      return INTEGER_ELT(from, 0);
+    }
+  }
+
+  // Also allow NA values
+  if (Rf_isLogical(from)) {
+    if (Rf_xlength(from) == 1) {
+      if (LOGICAL_ELT(from, 0) == NA_LOGICAL) {
+        return NA_REAL;
+      }
+    }
+  }
+
+  stop("Expected single double value");
+}
+
+template <typename T>
+enable_if_char<T, T> as_cpp(SEXP from) {
+  if (Rf_isString(from)) {
+    if (Rf_xlength(from) == 1) {
+      return unwind_protect([&] { return Rf_translateCharUTF8(STRING_ELT(from, 0))[0]; });
+    }
+  }
+
+  stop("Expected string vector of length 1");
+}
+
+template <typename T>
+enable_if_c_string<T, T> as_cpp(SEXP from) {
+  if (Rf_isString(from)) {
+    if (Rf_xlength(from) == 1) {
+      // TODO: use vmaxget / vmaxset here?
+      return {unwind_protect([&] { return Rf_translateCharUTF8(STRING_ELT(from, 0)); })};
+    }
+  }
+
+  stop("Expected string vector of length 1");
+}
+
+template <typename T>
+enable_if_std_string<T, T> as_cpp(SEXP from) {
+  return {as_cpp<const char*>(from)};
+}
+
+/// Temporary workaround for compatibility with cpp11 0.1.0
+template <typename T>
+enable_if_t<!std::is_same<decay_t<T>, T>::value, decay_t<T>> as_cpp(SEXP from) {
+  return as_cpp<decay_t<T>>(from);
+}
+
+template <typename T>
+enable_if_integral<T, SEXP> as_sexp(T from) {
+  return safe[Rf_ScalarInteger](from);
+}
+
+template <typename T>
+enable_if_floating_point<T, SEXP> as_sexp(T from) {
+  return safe[Rf_ScalarReal](from);
+}
+
+template <typename T>
+enable_if_bool<T, SEXP> as_sexp(T from) {
+  return safe[Rf_ScalarLogical](from);
+}
+
+template <typename T>
+enable_if_c_string<T, SEXP> as_sexp(T from) {
+  return unwind_protect([&] { return Rf_ScalarString(Rf_mkCharCE(from, CE_UTF8)); });
+}
+
+template <typename T>
+enable_if_std_string<T, SEXP> as_sexp(const T& from) {
+  return as_sexp(from.c_str());
+}
+
+template <typename Container, typename T = typename Container::value_type,
+          typename = disable_if_convertible_to_sexp<Container>>
+enable_if_integral<T, SEXP> as_sexp(const Container& from) {
+  R_xlen_t size = from.size();
+  SEXP data = safe[Rf_allocVector](INTSXP, size);
+
+  auto it = from.begin();
+  int* data_p = INTEGER(data);
+  for (R_xlen_t i = 0; i < size; ++i, ++it) {
+    data_p[i] = *it;
+  }
+  return data;
+}
+
+inline SEXP as_sexp(std::initializer_list<int> from) {
+  return as_sexp<std::initializer_list<int>>(from);
+}
+
+template <typename Container, typename T = typename Container::value_type,
+          typename = disable_if_convertible_to_sexp<Container>>
+enable_if_floating_point<T, SEXP> as_sexp(const Container& from) {
+  R_xlen_t size = from.size();
+  SEXP data = safe[Rf_allocVector](REALSXP, size);
+
+  auto it = from.begin();
+  double* data_p = REAL(data);
+  for (R_xlen_t i = 0; i < size; ++i, ++it) {
+    data_p[i] = *it;
+  }
+  return data;
+}
+
+inline SEXP as_sexp(std::initializer_list<double> from) {
+  return as_sexp<std::initializer_list<double>>(from);
+}
+
+template <typename Container, typename T = typename Container::value_type,
+          typename = disable_if_convertible_to_sexp<Container>>
+enable_if_bool<T, SEXP> as_sexp(const Container& from) {
+  R_xlen_t size = from.size();
+  SEXP data = safe[Rf_allocVector](LGLSXP, size);
+
+  auto it = from.begin();
+  int* data_p = LOGICAL(data);
+  for (R_xlen_t i = 0; i < size; ++i, ++it) {
+    data_p[i] = *it;
+  }
+  return data;
+}
+
+inline SEXP as_sexp(std::initializer_list<bool> from) {
+  return as_sexp<std::initializer_list<bool>>(from);
+}
+
+namespace detail {
+template <typename Container, typename AsCstring>
+SEXP as_sexp_strings(const Container& from, AsCstring&& c_str) {
+  R_xlen_t size = from.size();
+
+  SEXP data;
+  try {
+    data = PROTECT(safe[Rf_allocVector](STRSXP, size));
+
+    auto it = from.begin();
+    for (R_xlen_t i = 0; i < size; ++i, ++it) {
+      SET_STRING_ELT(data, i, safe[Rf_mkCharCE](c_str(*it), CE_UTF8));
+    }
+  } catch (const unwind_exception& e) {
+    UNPROTECT(1);
+    throw e;
+  }
+
+  UNPROTECT(1);
+  return data;
+}
+}  // namespace detail
+
+class r_string;
+
+template <typename T, typename R = void>
+using disable_if_r_string = enable_if_t<!std::is_same<T, cpp11::r_string>::value, R>;
+
+template <typename Container, typename T = typename Container::value_type,
+          typename = disable_if_r_string<T>>
+enable_if_t<std::is_convertible<T, std::string>::value &&
+                !std::is_convertible<T, const char*>::value,
+            SEXP>
+as_sexp(const Container& from) {
+  return detail::as_sexp_strings(from, [](const std::string& s) { return s.c_str(); });
+}
+
+template <typename Container, typename T = typename Container::value_type>
+enable_if_c_string<T, SEXP> as_sexp(const Container& from) {
+  return detail::as_sexp_strings(from, [](const char* s) { return s; });
+}
+
+inline SEXP as_sexp(std::initializer_list<const char*> from) {
+  return as_sexp<std::initializer_list<const char*>>(from);
+}
+
+template <typename T, typename = disable_if_r_string<T>>
+enable_if_convertible_to_sexp<T, SEXP> as_sexp(const T& from) {
+  return from;
+}
+
+}  // namespace cpp11