From 06f75b2b3072b3e7a8e6cb6755208deb9c603d63 Mon Sep 17 00:00:00 2001
From: Francesco Biscani <bluescarni@gmail.com>
Date: Wed, 13 Sep 2023 09:33:44 +0200
Subject: [PATCH] Add several noexcept decorations to the numbers API.

---
 include/heyoka/number.hpp | 18 +++++++++---------
 src/number.cpp            | 23 ++++++++++++++---------
 2 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/include/heyoka/number.hpp b/include/heyoka/number.hpp
index 8c3d9d17f..eef551436 100644
--- a/include/heyoka/number.hpp
+++ b/include/heyoka/number.hpp
@@ -70,12 +70,12 @@ class HEYOKA_DLL_PUBLIC number
     }
 
 public:
-    number();
-    explicit number(float);
-    explicit number(double);
-    explicit number(long double);
+    number() noexcept;
+    explicit number(float) noexcept;
+    explicit number(double) noexcept;
+    explicit number(long double) noexcept;
 #if defined(HEYOKA_HAVE_REAL128)
-    explicit number(mppp::real128);
+    explicit number(mppp::real128) noexcept;
 #endif
 #if defined(HEYOKA_HAVE_REAL)
     explicit number(mppp::real);
@@ -87,7 +87,7 @@ class HEYOKA_DLL_PUBLIC number
     number &operator=(const number &);
     number &operator=(number &&) noexcept;
 
-    [[nodiscard]] const value_type &value() const;
+    [[nodiscard]] const value_type &value() const noexcept;
 };
 
 namespace detail
@@ -113,9 +113,9 @@ HEYOKA_DLL_PUBLIC number operator-(const number &, const number &);
 HEYOKA_DLL_PUBLIC number operator*(const number &, const number &);
 HEYOKA_DLL_PUBLIC number operator/(const number &, const number &);
 
-HEYOKA_DLL_PUBLIC bool operator==(const number &, const number &);
-HEYOKA_DLL_PUBLIC bool operator!=(const number &, const number &);
-HEYOKA_DLL_PUBLIC bool operator<(const number &, const number &);
+HEYOKA_DLL_PUBLIC bool operator==(const number &, const number &) noexcept;
+HEYOKA_DLL_PUBLIC bool operator!=(const number &, const number &) noexcept;
+HEYOKA_DLL_PUBLIC bool operator<(const number &, const number &) noexcept;
 
 HEYOKA_DLL_PUBLIC number exp(const number &);
 HEYOKA_DLL_PUBLIC number binomial(const number &, const number &);
diff --git a/src/number.cpp b/src/number.cpp
index 8e1036390..e29b6610a 100644
--- a/src/number.cpp
+++ b/src/number.cpp
@@ -72,17 +72,17 @@
 
 HEYOKA_BEGIN_NAMESPACE
 
-number::number() : number(0.) {}
+number::number() noexcept : number(0.) {}
 
-number::number(float x) : m_value(x) {}
+number::number(float x) noexcept : m_value(x) {}
 
-number::number(double x) : m_value(x) {}
+number::number(double x) noexcept : m_value(x) {}
 
-number::number(long double x) : m_value(x) {}
+number::number(long double x) noexcept : m_value(x) {}
 
 #if defined(HEYOKA_HAVE_REAL128)
 
-number::number(mppp::real128 x) : m_value(x) {}
+number::number(mppp::real128 x) noexcept : m_value(x) {}
 
 #endif
 
@@ -126,7 +126,7 @@ number &number::operator=(number &&other) noexcept
     return *this;
 }
 
-const number::value_type &number::value() const
+const number::value_type &number::value() const noexcept
 {
     return m_value;
 }
@@ -253,6 +253,11 @@ bool is_integer(const number &n)
         n.value());
 }
 
+number operator+(number n)
+{
+    return n;
+}
+
 number operator-(const number &n)
 {
     return std::visit([](const auto &arg) { return number{-arg}; }, n.value());
@@ -377,7 +382,7 @@ number operator/(const number &n1, const number &n2)
 // verifying decompositions: when the original expression is
 // reconstructed from the subexpressions and we compare, the
 // check would fail due to NaN != NaN.
-bool operator==(const number &n1, const number &n2)
+bool operator==(const number &n1, const number &n2) noexcept
 {
     return std::visit(
         [](const auto &v1, const auto &v2) -> bool {
@@ -396,7 +401,7 @@ bool operator==(const number &n1, const number &n2)
         n1.value(), n2.value());
 }
 
-bool operator!=(const number &n1, const number &n2)
+bool operator!=(const number &n1, const number &n2) noexcept
 {
     return !(n1 == n2);
 }
@@ -405,7 +410,7 @@ bool operator!=(const number &n1, const number &n2)
 // same type in order to be considered equivalent. Also, NaNs are considered
 // greater than any other value, so that they will be placed at the
 // end of a sorted range.
-bool operator<(const number &n1, const number &n2)
+bool operator<(const number &n1, const number &n2) noexcept
 {
     return std::visit(
         [&](const auto &v1, const auto &v2) -> bool {