From 5baf5d3daeece33e0767a1c8fbd1b85daa84f45e Mon Sep 17 00:00:00 2001 From: EnilPajic Date: Fri, 26 Jun 2020 21:25:39 +0200 Subject: Fixed potential bug with -MINIMUM_VALUE Original code had something like `N < 0 ? -N : N` which could fail if `N` has minimum value of appropriate type. For example, in original code this could fail: ```cpp const long long int LL_MIN = std::numeric_limits::min(); //probably: -9223372036854775808 static const char *number = to_string; ``` Also note that this code relies on "modulo on negative first operands" which was implementation defined in C++03 and before, but with C++11 and later it is defined by standard (see `ISO14882:2011(e)`), and this code anyway targets C++17 so we're safe here. --- to_string.hpp | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'to_string.hpp') diff --git a/to_string.hpp b/to_string.hpp index 116cdd8..6117258 100644 --- a/to_string.hpp +++ b/to_string.hpp @@ -23,7 +23,7 @@ struct to_string_t { // fits to the number perfectly. char buf[([] { unsigned int len = N >= 0 ? 1 : 2; - for (auto n = N < 0 ? -N : N; n; len++, n /= base); + for (auto n = N; n; len++, n /= base); return len; }())]; @@ -33,8 +33,8 @@ struct to_string_t { constexpr to_string_t() { auto ptr = buf + sizeof(buf) / sizeof(buf[0]); *--ptr = '\0'; - for (auto n = N < 0 ? -N : N; n; n /= base) - *--ptr = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"[n % base]; + for (auto n = N; n; n /= base) + *--ptr = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"[(N < 0 ? -1 : 1) * (n % base)]; if (N < 0) *--ptr = '-'; } -- cgit v1.2.3 From 9aa286ebc05d36f7ce4b4c840ac43904a8cc7ade Mon Sep 17 00:00:00 2001 From: neargye Date: Sat, 27 Jun 2020 21:35:10 +0500 Subject: container-like --- to_string.hpp | 33 ++++++++++++++++++++++----------- 1 file changed, 22 insertions(+), 11 deletions(-) (limited to 'to_string.hpp') diff --git a/to_string.hpp b/to_string.hpp index 1d88b1a..b9e0cce 100644 --- a/to_string.hpp +++ b/to_string.hpp @@ -18,15 +18,16 @@ template, int> = 0, std::enable_if_t<(base > 1 && base < 37), int> = 0> -struct to_string_t { +class to_string_t { // The lambda calculates what the string length of N will be, so that `buf` // fits to the number perfectly. - char_type buf[([] { + char_type buf[([]() constexpr noexcept { unsigned int len = N > 0 ? 1 : 2; for (auto n = N < 0 ? -N : N; n; len++, n /= base); return len; }())] = {}; + public: /** * Constructs the object, filling `buf` with the string representation of N. */ @@ -44,14 +45,24 @@ struct to_string_t { } // Support implicit casting to `char *` or `const char *`. - constexpr operator char_type *() { return buf; } - constexpr operator const char_type *() const { return buf; } - - // Support range-based for loops - constexpr auto begin() { return buf; } - constexpr auto begin() const { return buf; } - constexpr auto end() { return buf + sizeof(buf) / sizeof(buf[0]); } - constexpr auto end() const { return buf + sizeof(buf) / sizeof(buf[0]); } + constexpr operator char_type *() noexcept { return buf; } + constexpr operator const char_type *() const noexcept { return buf; } + + constexpr auto size() const noexcept { return sizeof(buf) / sizeof(buf[0]); } + // Element access + constexpr auto data() noexcept { return buf; } + constexpr auto data() const noexcept { return buf; } + constexpr auto operator[](unsigned int i) noexcept { return buf[i]; } + constexpr auto operator[](unsigned int i) const noexcept { return buf[i]; } + constexpr auto front() noexcept { return buf[0]; } + constexpr auto front() const noexcept { return buf[0]; } + constexpr auto back() noexcept { return buf[size() - 1]; } + constexpr auto back() const noexcept { return buf[size() - 1]; } + // Iterators + constexpr auto begin() noexcept { return buf; } + constexpr auto begin() const noexcept { return buf; } + constexpr auto end() noexcept { return buf + size(); } + constexpr auto end() const noexcept { return buf + size(); } }; /** @@ -59,5 +70,5 @@ struct to_string_t { */ template constexpr to_string_t to_string; - + #endif // TCSULLIVAN_TO_STRING_HPP_ -- cgit v1.2.3 From e395be3782f7adf92dbdd1e7438ea038eebecdf3 Mon Sep 17 00:00:00 2001 From: Clyne Sullivan Date: Sat, 27 Jun 2020 18:31:53 -0400 Subject: Use end() in constructor --- to_string.hpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'to_string.hpp') diff --git a/to_string.hpp b/to_string.hpp index b9e0cce..11e5906 100644 --- a/to_string.hpp +++ b/to_string.hpp @@ -32,9 +32,9 @@ class to_string_t { * Constructs the object, filling `buf` with the string representation of N. */ constexpr to_string_t() noexcept { + auto ptr = end(); + *--ptr = '\0'; if (N != 0) { - auto ptr = buf + sizeof(buf) / sizeof(buf[0]); - *--ptr = '\0'; for (auto n = N < 0 ? -N : N; n; n /= base) *--ptr = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"[n % base]; if (N < 0) -- cgit v1.2.3 From 6ae484c8011dc5f10b552932dd3b977b46b4a1f5 Mon Sep 17 00:00:00 2001 From: Clyne Sullivan Date: Sat, 27 Jun 2020 18:37:33 -0400 Subject: add const and references to container operations --- to_string.hpp | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'to_string.hpp') diff --git a/to_string.hpp b/to_string.hpp index 11e5906..3f04272 100644 --- a/to_string.hpp +++ b/to_string.hpp @@ -51,18 +51,18 @@ class to_string_t { constexpr auto size() const noexcept { return sizeof(buf) / sizeof(buf[0]); } // Element access constexpr auto data() noexcept { return buf; } - constexpr auto data() const noexcept { return buf; } - constexpr auto operator[](unsigned int i) noexcept { return buf[i]; } - constexpr auto operator[](unsigned int i) const noexcept { return buf[i]; } - constexpr auto front() noexcept { return buf[0]; } - constexpr auto front() const noexcept { return buf[0]; } - constexpr auto back() noexcept { return buf[size() - 1]; } - constexpr auto back() const noexcept { return buf[size() - 1]; } + constexpr const auto data() const noexcept { return buf; } + constexpr auto& operator[](unsigned int i) noexcept { return buf[i]; } + constexpr const auto& operator[](unsigned int i) const noexcept { return buf[i]; } + constexpr auto& front() noexcept { return buf[0]; } + constexpr const auto& front() const noexcept { return buf[0]; } + constexpr auto& back() noexcept { return buf[size() - 1]; } + constexpr const auto& back() const noexcept { return buf[size() - 1]; } // Iterators constexpr auto begin() noexcept { return buf; } - constexpr auto begin() const noexcept { return buf; } + constexpr const auto begin() const noexcept { return buf; } constexpr auto end() noexcept { return buf + size(); } - constexpr auto end() const noexcept { return buf + size(); } + constexpr const auto end() const noexcept { return buf + size(); } }; /** -- cgit v1.2.3 From 6e7939000f22dbc955d5aa7feff4db5541205e98 Mon Sep 17 00:00:00 2001 From: clyne Date: Sat, 27 Jun 2020 19:08:48 -0400 Subject: Change base from unsigned to signed --- to_string.hpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'to_string.hpp') diff --git a/to_string.hpp b/to_string.hpp index bf724cd..e7eef93 100644 --- a/to_string.hpp +++ b/to_string.hpp @@ -15,7 +15,7 @@ * @tparam N Number to convert * @tparam base Desired base, can be from 2 to 36 */ -template, int> = 0, std::enable_if_t<(base > 1 && base < 37), int> = 0> class to_string_t { @@ -35,7 +35,7 @@ class to_string_t { auto ptr = end(); *--ptr = '\0'; if (N != 0) { - for (auto n = N < 0 ? -N : N; n; n /= base) + for (auto n = N; n; n /= base) *--ptr = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"[(N < 0 ? -1 : 1) * (n % base)]; if (N < 0) *--ptr = '-'; -- cgit v1.2.3 From 56692725154d1e4ff2ef4786107cfda81c44b192 Mon Sep 17 00:00:00 2001 From: clyne Date: Sat, 27 Jun 2020 19:13:18 -0400 Subject: Changed other base instance to signed --- to_string.hpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'to_string.hpp') diff --git a/to_string.hpp b/to_string.hpp index e7eef93..eb363f0 100644 --- a/to_string.hpp +++ b/to_string.hpp @@ -68,7 +68,7 @@ class to_string_t { /** * Simplifies use of `to_string_t` from `to_string_t()` to `to_string`. */ -template +template constexpr to_string_t to_string; #endif // TCSULLIVAN_TO_STRING_HPP_ -- cgit v1.2.3