Merge pull request #41 from saxbophone/josh/implement-string-ctor

Implement string constructor

Author: saxbophone

arby/src/arby.cpp

@@ -14,7 +14,10 @@
 
 
 namespace com::saxbophone::arby {
-    Uint::Uint(std::string digits) {}
+    Uint::Uint(std::string digits)
+        // use user-defined-literal to convert the digits in the string
+      : _digits(operator "" _uarb(digits.c_str())._digits)
+      {}
 
     std::string Uint::_stringify_for_base() const {
         // XXX: only base-10 implemented for now

tests/basic_arithmetic.cpp

@@ -1,6 +1,7 @@
 #include <compare>
 #include <limits>
 #include <stdexcept>
+#include <string>
 
 #include <catch2/catch.hpp>
 
@@ -65,6 +66,15 @@ TEST_CASE("arby::Uint(UINT_MAX) and (uintmax_t)arby::Uint", "[ctor]") {
     CHECK((uintmax_t)output == std::numeric_limits<uintmax_t>::max());
 }
 
+TEST_CASE("arby::Uint(std::string)", "[ctor]") {
+    uintmax_t value = GENERATE(take(1000, random((uintmax_t)0, std::numeric_limits<uintmax_t>::max())));
+    std::string string = std::to_string(value);
+
+    arby::Uint object = string;
+
+    CHECK((uintmax_t)object == value);
+}
+
 // only inlude these tests if we have library support for constexpr vector
 #ifdef __cpp_lib_constexpr_vector
 TEST_CASE("constexpr arby::Uint", "[constexpr]") {