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Revert "Use if constexpr to make things a lot more readable"

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This reverts commit d62ca9f879.
This commit is contained in:
louiz’
2018-03-17 17:28:41 +01:00
parent d62ca9f879
commit d0e3c71b91
7 changed files with 213 additions and 164 deletions
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src/database/select_query.hpp
+45 -32
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@@ -15,37 +15,48 @@
using namespace std::string_literals;
template <typename T>
auto extract_row_value(Statement& statement, const int i)
typename std::enable_if<std::is_integral<T>::value, std::int64_t>::type
extract_row_value(Statement& statement, const int i)
{
if constexpr(std::is_integral<T>::value)
return statement.get_column_int64(i);
else if constexpr (std::is_same<std::string, T>::value)
return statement.get_column_text(i);
else if (std::is_same<std::optional<bool>, T>::value)
{
const auto integer = statement.get_column_int(i);
if (integer > 0)
return std::optional<bool>{true};
else if (integer < 0)
return std::optional<bool>{false};
return std::optional<bool>{};
}
return statement.get_column_int64(i);
}
template <typename T>
typename std::enable_if<std::is_same<std::string, T>::value, T>::type
extract_row_value(Statement& statement, const int i)
{
return statement.get_column_text(i);
}
template <typename T>
typename std::enable_if<std::is_same<std::optional<bool>, T>::value, T>::type
extract_row_value(Statement& statement, const int i)
{
const auto integer = statement.get_column_int(i);
if (integer > 0)
return true;
else if (integer < 0)
return false;
return std::nullopt;
}
template <std::size_t N=0, typename... T>
void extract_row_values(Row<T...>& row, Statement& statement)
typename std::enable_if<N < sizeof...(T), void>::type
extract_row_values(Row<T...>& row, Statement& statement)
{
if constexpr(N < sizeof...(T))
{
using ColumnType = typename std::remove_reference<decltype(std::get<N>(row.columns))>::type;
using ColumnType = typename std::remove_reference<decltype(std::get<N>(row.columns))>::type;
auto&& column = std::get<N>(row.columns);
column.value = static_cast<decltype(column.value)>(extract_row_value<typename ColumnType::real_type>(statement, N));
auto&& column = std::get<N>(row.columns);
column.value = static_cast<decltype(column.value)>(extract_row_value<typename ColumnType::real_type>(statement, N));
extract_row_values<N + 1>(row, statement);
}
extract_row_values<N+1>(row, statement);
}
template <std::size_t N=0, typename... T>
typename std::enable_if<N == sizeof...(T), void>::type
extract_row_values(Row<T...>&, Statement&)
{}
template <typename... T>
struct SelectQuery: public Query
{
@@ -58,21 +69,23 @@ struct SelectQuery: public Query
}
template <std::size_t N=0>
void insert_col_name()
typename std::enable_if<N < sizeof...(T), void>::type
insert_col_name()
{
if constexpr(N < sizeof...(T))
{
using ColumnsType = std::tuple<T...>;
using ColumnType = typename std::remove_reference<decltype(std::get<N>(std::declval<ColumnsType>()))>::type;
using ColumnsType = std::tuple<T...>;
using ColumnType = typename std::remove_reference<decltype(std::get<N>(std::declval<ColumnsType>()))>::type;
this->body += " " + std::string{ColumnType::name};
this->body += " " + std::string{ColumnType::name};
if (N < (sizeof...(T) - 1))
this->body += ", ";
if (N < (sizeof...(T) - 1))
this->body += ", ";
this->insert_col_name<N + 1>();
}
this->insert_col_name<N+1>();
}
template <std::size_t N=0>
typename std::enable_if<N == sizeof...(T), void>::type
insert_col_name()
{}
SelectQuery& where()
{