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Reovered example value (field)

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This commit is contained in:
Ruben Perez 2022-10-20 11:35:57 +02:00
parent 6164b878e6
commit 9fe98dd83b
3 changed files with 51 additions and 133 deletions
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2
example/CMakeLists.txt
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@ -65,7 +65,7 @@ endif()
# Build and run all the examples
if (BOOST_MYSQL_INTEGRATION_TESTS)
add_example(tutorial TRUE ${SERVER_HOST})
# add_example(value TRUE ${SERVER_HOST})
add_example(field TRUE ${SERVER_HOST})
add_example(query_sync TRUE ${SERVER_HOST})
add_example(query_async_callbacks TRUE ${SERVER_HOST})
add_example(query_async_coroutines FALSE ${SERVER_HOST})

50
example/field.cpp Normal file
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@ -0,0 +1,50 @@
//
// Copyright (c) 2019-2022 Ruben Perez Hidalgo (rubenperez038 at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include <boost/mysql/field_view.hpp>
#include <iostream>
#define ASSERT(expr) \
if (!(expr)) \
{ \
std::cerr << "Assertion failed: " #expr << std::endl; \
exit(1); \
}
void example_as()
{
//[value_example_get
boost::mysql::field_view v("hello"); // v contains type boost::string_view
boost::string_view typed_val = v.as_string(); // retrieves the underlying string
ASSERT(typed_val == "hello");
try
{
v.as_double(); // wrong type! throws boost::mysql::bad_field_access
// v.get_double(); // don't do this - UB
}
catch (const boost::mysql::bad_field_access&)
{
}
//]
}
void example_is()
{
//[value_example_is
boost::mysql::field_view v(std::uint64_t(42)); // v contains type std::uint64_t
ASSERT(v.is_uint64()); // exact type match
ASSERT(!v.is_int64()); // the underlying type is unsigned
ASSERT(!v.is_string());
//]
}
int main()
{
example_as();
example_is();
}

132
example/value.cpp
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@ -1,132 +0,0 @@
//
// Copyright (c) 2019-2022 Ruben Perez Hidalgo (rubenperez038 at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include <boost/mysql/field_view.hpp>
#include <iostream>
#define ASSERT(expr) \
if (!(expr)) \
{ \
std::cerr << "Assertion failed: " #expr << std::endl; \
exit(1); \
}
void example_get()
{
//[value_example_get
boost::mysql::field_view v ("hello"); // v contains type boost::string_view
boost::string_view typed_val = v.get<boost::string_view>(); // retrieves the underlying string
ASSERT(typed_val == "hello");
try
{
v.get<double>(); // wrong type! throws boost::mysql::bad_value_access
}
catch (const boost::mysql::bad_field_access&)
{
}
//]
}
void example_get_optional()
{
//[value_example_get_optional
boost::mysql::field_view v (3.14); // v contains type double
boost::optional<double> typed_val = v.get_optional<double>();
ASSERT(typed_val.has_value()); // the optional is not empty
ASSERT(*typed_val == 3.14); // and contains the right value
boost::optional<boost::string_view> other =
v.get_optional<boost::string_view>(); // wrong type!
ASSERT(!other.has_value()); // empty optional
//]
}
#ifndef BOOST_NO_CXX17_HDR_OPTIONAL
void example_get_std_optional()
{
//[value_example_get_std_optional
boost::mysql::field_view v (3.14); // v contains type double
std::optional<double> typed_val = v.get_std_optional<double>();
ASSERT(typed_val.has_value()); // the optional is not empty
ASSERT(*typed_val == 3.14); // and contains the right value
std::optional<boost::string_view> other =
v.get_std_optional<boost::string_view>(); // wrong type!
ASSERT(!other.has_value()); // empty optional
//]
}
#endif
void example_get_conversions()
{
//[value_example_get_conversions
boost::mysql::field_view v (std::uint64_t(42)); // v contains type std::uint64_t
ASSERT(v.get<std::uint64_t>() == 42u); // exact type match
ASSERT(v.get<std::int64_t>() == 42); // converts from std::uint64_t -> std::int64_t
//]
}
void example_inefficient()
{
//[value_example_inefficient
// WARNING!! Inefficient, do NOT do
boost::mysql::field_view v (3.14); // get the value e.g. using query
if (v.is_convertible_to<double>()) // it should be double, but we are not use
{
double val = v.get<double>();
// Do stuff with val
ASSERT(val == 3.14);
}
else
{
// oops, value didn't contain a double, handle the error
}
//]
}
void example_inefficient_ok()
{
//[value_example_inefficient_ok
boost::mysql::field_view v (3.14); // get the value e.g. using query
boost::optional<double> val = v.get_optional<double>();
// it should be double, but we are not use
if (val)
{
// Do stuff with val
ASSERT(*val == 3.14);
}
else
{
// oops, value didn't contain a double, handle the error
}
//]
}
void example_is()
{
//[value_example_is
boost::mysql::field_view v (std::uint64_t(42)); // v contains type std::uint64_t
ASSERT(v.is<std::uint64_t>()); // exact type match
ASSERT(!v.is<std::int64_t>()); // does not consider conversions
ASSERT(v.is_convertible_to<std::uint64_t>()); // exact type match
ASSERT(v.is_convertible_to<std::int64_t>()); // considers conversions
//]
}
int main()
{
example_get();
example_get_optional();
#ifndef BOOST_NO_CXX17_HDR_OPTIONAL
example_get_std_optional();
#endif
example_get_conversions();
example_inefficient();
example_inefficient_ok();
example_is();
}