Add Fastor library

noarch/include/Fastor/util/extended_algorithms.h

@@ -0,0 +1,99 @@
+#ifndef EXTENDED_ALGORITHMS_H
+#define EXTENDED_ALGORITHMS_H
+
+#include <algorithm>
+#include <functional>
+#include <utility>
+#include <type_traits>
+#include <array>
+#include <vector>
+#include <numeric>
+#include <cstring>
+
+#if defined(FASTOR_UNIX_OS)
+#include <sys/resource.h>
+#endif
+
+namespace Fastor {
+
+// Implementation of STL iota to work on other types such as
+// std::complex. For std::complex iota_impl increments the real
+// part only
+template<class ForwardIt, class T>
+inline void iota_impl(ForwardIt first, ForwardIt last, T value)
+{
+    while(first != last) {
+        *first++ = value;
+        value += T(1);
+    }
+}
+
+template <typename T, size_t N>
+inline std::array<int,N> argsort(const std::array<T,N> &v) {
+  std::array<int,N> idx;
+  std::iota(idx.begin(),idx.end(),0);
+  std::sort(idx.begin(), idx.end(), [&v](int i1, int i2) {return v[i1] < v[i2];});
+  return idx;
+}
+
+
+template<typename T, size_t N, typename std::enable_if<std::is_arithmetic<T>::value,bool>::type = 0>
+inline std::string itoa(const std::array<T,N>& arr) {
+    std::string out = std::to_string(arr[0]);
+    for (size_t i=1; i<N; ++i)
+        out += ","+std::to_string(arr[i]);
+    return out;
+}
+
+
+#if defined(FASTOR_UNIX_OS)
+inline size_t set_stack_size(size_t size) {
+    // If the function does not work, copy-paste it within
+    // the body of the main
+
+    // size is stack size in MB (for instance provide 80 for 80MB)
+    // returns old stack size in MB
+    const rlim_t stacksize = size*1024*1024;
+    struct rlimit rl;
+    int result;
+    result = getrlimit(RLIMIT_STACK, &rl);
+    rlim_t old = rl.rlim_cur = stacksize;
+    if (result==0) {
+        if (rl.rlim_cur < stacksize) {
+            rl.rlim_cur = stacksize;
+            result = setrlimit(RLIMIT_STACK,&rl);
+            FASTOR_ASSERT(result !=0, "CHANGING STACK SIZE FAILED");
+        }
+    }
+
+    return old;
+}
+#endif
+
+
+
+// Get sign of a number
+template <typename T>
+inline constexpr int signum(T x, [[gnu::unused]] std::false_type is_signed) {
+    return T(0) < x;
+}
+template <typename T>
+inline constexpr int signum(T x, [[gnu::unused]] std::true_type is_signed) {
+    return (T(0) < x) - (x < T(0));
+}
+template <typename T>
+inline constexpr int signum(T x) {
+    return signum(x, std::is_signed<T>());
+}
+
+// Get a string +/- based on sign
+template <typename T> std::string signum_string(T val) {
+    return signum(val) == 1 ? "+" : "-";
+}
+
+
+} // end of namespace Fastor
+
+
+#endif // EXTENDED_ALGORITHMS_H
+