feedc0de/boost_static_string
1
0
Fork 0
forked from boostorg/static_string
Code Pull Requests Activity

More constexpr friendly replace and insert with is_constant_evaluated

Browse Source
This commit is contained in:
Krystian Stasiowski
2020-01-03 19:01:34 -05:00
parent e1e992380a
commit 26b9f7df27
3 changed files with 33 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
include/boost/static_string/config.hpp
View File

@ -25,6 +25,16 @@
#define BOOST_STATIC_STRING_USE_DEDUCT #define BOOST_STATIC_STRING_USE_DEDUCT
#endif #endif
// Include <version> if we can
#if __has_include(<version>)
#include <version>
#endif
// Can we use is_constant_evaluated?
#if __cpp_lib_is_constant_evaluated >= 201811L
#define BOOST_STATIC_STRING_USE_IS_CONST_EVAL
#endif
// Can we use [[nodiscard]]? // Can we use [[nodiscard]]?
#ifdef __has_attribute #ifdef __has_attribute
#if __has_attribute(nodiscard) #if __has_attribute(nodiscard)

20
include/boost/static_string/impl/static_string.hpp
View File

@ -363,7 +363,15 @@ insert(
const auto s = &*first; const auto s = &*first;
BOOST_STATIC_STRING_THROW_IF( BOOST_STATIC_STRING_THROW_IF(
count > max_size() - curr_size, std::length_error{"count > max_size() - size()"}); count > max_size() - curr_size, std::length_error{"count > max_size() - size()"});
const bool inside = s <= &curr_data[curr_size] && s >= curr_data; // Makes this more constexpr friendly if we can use is_constant_evaluated
const bool inside =
#ifdef BOOST_STATIC_STRING_USE_IS_CONST_EVAL
std::is_constant_evaluated() ?
detail::is_inside(curr_data, curr_data + curr_size, s) :
s <= &curr_data[curr_size] && s >= curr_data;
#else
s <= &curr_data[curr_size] && s >= curr_data;
#endif
if (!inside || (inside && ((s - curr_data) + count <= index))) if (!inside || (inside && ((s - curr_data) + count <= index)))
{ {
Traits::move(&curr_data[index + count], &curr_data[index], curr_size - index + 1); Traits::move(&curr_data[index + count], &curr_data[index], curr_size - index + 1);
@ -683,7 +691,15 @@ replace(
curr_size - (std::min)(n1, curr_size - pos) >= max_size() - n2, curr_size - (std::min)(n1, curr_size - pos) >= max_size() - n2,
std::length_error{"replaced string exceeds max_size()"}); std::length_error{"replaced string exceeds max_size()"});
n1 = (std::min)(n1, curr_size - pos); n1 = (std::min)(n1, curr_size - pos);
const bool inside = s <= &curr_data[curr_size] && s >= curr_data; // Makes this more constexpr friendly if we can use is_constant_evaluated
const bool inside =
#ifdef BOOST_STATIC_STRING_USE_IS_CONST_EVAL
std::is_constant_evaluated() ?
detail::is_inside(curr_data, curr_data + curr_size, s) :
s <= &curr_data[curr_size] && s >= curr_data;
#else
s <= &curr_data[curr_size] && s >= curr_data;
#endif
if (inside && size_type(s - curr_data) == pos && n1 == n2) if (inside && size_type(s - curr_data) == pos && n1 == n2)
return *this; return *this;
if (!inside || (inside && ((s - curr_data) + n2 <= pos))) if (!inside || (inside && ((s - curr_data) + n2 <= pos)))

5
test/constexpr_tests.hpp
View File

@ -191,6 +191,11 @@ testConstantEvaluation()
a.replace(a.begin(), a.end(), a.begin(), a.end()); a.replace(a.begin(), a.end(), a.begin(), a.end());
a.replace(a.begin(), a.end(), {'a'}); a.replace(a.begin(), a.end(), {'a'});
#ifdef BOOST_STATIC_STRING_USE_IS_CONST_EVAL
a.replace(a.begin(), a.end(), "a");
a.replace(a.begin(), a.end(), "a", 1);
#endif
// find // find
a.find(a); a.find(a);
a.find("a", 0, 1); a.find("a", 0, 1);