boost/leaf
2
0
Fork 0
mirror of https://github.com/boostorg/leaf.git synced 2026-01-19 04:22:08 +00:00
Code Issues Projects Releases Wiki Activity

BOOST_LEAF_VAR renamed to BOOST_LEAF_ASSIGN

Browse Source
This commit is contained in:
Emil Dotchevski
2020-07-06 12:22:26 -07:00
parent 6a1b812d03
commit ae08413380
7 changed files with 30 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
.vscode/tasks.json vendored
View File

@@ -96,12 +96,12 @@
}
},
{
"label": "BOOST_LEAF_VAR_test",
"label": "BOOST_LEAF_ASSIGN_test",
"type": "shell",
"command": "cd ${workspaceRoot}/bld/debug && meson test BOOST_LEAF_VAR_test",
"command": "cd ${workspaceRoot}/bld/debug && meson test BOOST_LEAF_ASSIGN_test",
"problemMatcher": { "base": "$gcc", "fileLocation": ["relative","${workspaceRoot}/bld/debug"] },
"windows": {
"command": "${workspaceRoot}/.vscode/msvc.bat && cd ${workspaceRoot}/bld/debug && meson test BOOST_LEAF_VAR_test"
"command": "${workspaceRoot}/.vscode/msvc.bat && cd ${workspaceRoot}/bld/debug && meson test BOOST_LEAF_ASSIGN_test"
}
},
{

32
doc/leaf.adoc
View File

@@ -988,7 +988,7 @@ return leaf::try_handle_some(
----
[.text-right]
<<try_handle_some>> | <<result>> | <<BOOST_LEAF_VAR>>
<<try_handle_some>> | <<result>> | <<BOOST_LEAF_ASSIGN>>
The reason this works is that in case it communicates a failure, `leaf::result<T>` is able to hold a `shared_ptr<polymorphic_context>` object. That is why earlier instead of calling `task()` directly, we called `leaf::capture`: it calls the passed function and, in case that fails, it stores the `shared_ptr<polymorphic_context>` we created in the returned `result<T>`, which now doesn't just communicate the fact that an error has occurred, but also holds the `context` object that `try_handle_some` needs in order to supply a suitable handler with arguments.
@@ -1302,7 +1302,7 @@ leaf::result<void> print_answer() noexcept
----
[.text-right]
<<result>> | <<BOOST_LEAF_VAR>>
<<result>> | <<BOOST_LEAF_ASSIGN>>
Finally, here is a scope that handles the errors -- it will work correctly regardless of whether `error_a` and `error_b` objects are thrown as exceptions or not.
@@ -1485,7 +1485,7 @@ int main() noexcept
}
----
[.text-right]
<<try_handle_all>> | <<result>> | <<BOOST_LEAF_VAR>> | <<error_info>>
<<try_handle_all>> | <<result>> | <<BOOST_LEAF_ASSIGN>> | <<error_info>>
<1> If the call to `call_lua` succeeded, just print the answer.
<2> Handle `do_work` failures.
@@ -1920,14 +1920,14 @@ namespace boost { namespace leaf {
} }
#define BOOST_LEAF_VAR(v, r)\
#define BOOST_LEAF_ASSIGN(v, r)\
auto && <<temp>> = r;\
if( !<<temp>> )\
return <<temp>>.error();\
v = <<temp>>.value()
#define BOOST_LEAF_AUTO(v, r)\
BOOST_LEAF_VAR(auto && v, r)
BOOST_LEAF_ASSIGN(auto && v, r)
#define BOOST_LEAF_CHECK(r)\
{\
@@ -1940,7 +1940,7 @@ namespace boost { namespace leaf {
----
[.text-right]
Reference: <<error_id>> | <<is_error_id>> | <<new_error>> | <<current_error>> | <<polymorphic_context>> | <<context_activator>> | <<activate_context>> | <<is_result_type>> | <<BOOST_LEAF_VAR>> | <<BOOST_LEAF_AUTO>> | <<BOOST_LEAF_CHECK>> | <<BOOST_LEAF_NEW_ERROR>>
Reference: <<error_id>> | <<is_error_id>> | <<new_error>> | <<current_error>> | <<polymorphic_context>> | <<context_activator>> | <<activate_context>> | <<is_result_type>> | <<BOOST_LEAF_ASSIGN>> | <<BOOST_LEAF_AUTO>> | <<BOOST_LEAF_CHECK>> | <<BOOST_LEAF_NEW_ERROR>>
====
[[common.hpp]]
@@ -2628,7 +2628,7 @@ return leaf::try_handle_some(
----
[.text-right]
<<try_handle_some>> | <<result>> | <<BOOST_LEAF_VAR>>
<<try_handle_some>> | <<result>> | <<BOOST_LEAF_ASSIGN>>
WARNING: When a handler takes an argument of an exception type (that is, a type that derives from `std::exception`), if the object is thrown, the argument will be matched dynamically (using `dynamic_cast`); otherwise (e.g. after being converted by `exception_to_result`) it will be matched based on its static type only (which is the same behavior used for types that do not derive from `std::exception`).
@@ -4589,10 +4589,10 @@ TIP: The contents of each Reference section are organized alphabetically.
[source,c++]
----
#define BOOST_LEAF_AUTO(v, r)\
BOOST_LEAF_VAR(auto && v, r)
BOOST_LEAF_ASSIGN(auto && v, r)
----
[.text-right]
<<BOOST_LEAF_VAR>>
<<BOOST_LEAF_ASSIGN>>
`BOOST_LEAF_AUTO` is useful when calling a function that returns `result<T>` (other than `result<void>`), if the desired behavior is to forward any errors to the caller verbatim.
@@ -4628,7 +4628,7 @@ leaf::result<float> add_values()
}
----
NOTE: See also <<BOOST_LEAF_VAR>>.
NOTE: See also <<BOOST_LEAF_ASSIGN>>.
'''
@@ -4718,22 +4718,22 @@ Effects: :: Throws the exception object returned by <<BOOST_LEAF_EXCEPTION>>.
'''
[[BOOST_LEAF_VAR]]
=== `BOOST_LEAF_VAR`
[[BOOST_LEAF_ASSIGN]]
=== `BOOST_LEAF_ASSIGN`
.#include <boost/leaf/error.hpp>
[source,c++]
----
#define BOOST_LEAF_VAR(v, r)\
#define BOOST_LEAF_ASSIGN(v, r)\
auto && <<temp>> = r;\
if( !<<temp>> )\
return <<temp>>.error();\
v = <<temp>>.value()
----
`BOOST_LEAF_VAR` is useful when calling a function that returns `result<T>` (other than `result<void>`), if the desired behavior is to forward any errors to the caller verbatim.
`BOOST_LEAF_ASSIGN` is useful when calling a function that returns `result<T>` (other than `result<void>`), if the desired behavior is to forward any errors to the caller verbatim.
In case of success, the result `value()` of type `T` is assigned to the specified variable `v`, which must have been declared prior to invoking `BOOST_LEAF_VAR`. However, it is possible to use `BOOST_LEAF_VAR` to declare a new variable, by passing in `v` its type together with its name, e.g. `BOOST_LEAF_VAR(auto && x, f())` calls `f`, forwards errors to the caller, while capturing successful values in `x`.
In case of success, the result `value()` of type `T` is assigned to the specified variable `v`, which must have been declared prior to invoking `BOOST_LEAF_ASSIGN`. However, it is possible to use `BOOST_LEAF_ASSIGN` to declare a new variable, by passing in `v` its type together with its name, e.g. `BOOST_LEAF_ASSIGN(auto && x, f())` calls `f`, forwards errors to the caller, while capturing successful values in `x`.
NOTE: See also <<BOOST_LEAF_AUTO>>.
@@ -5038,7 +5038,7 @@ leaf::result<parsed_line> read_and_parse_line( reader & r )
}
----
[.text-right]
<<result>> | <<BOOST_LEAF_VAR>>
<<result>> | <<BOOST_LEAF_ASSIGN>>
<1> Read a line, forward errors to the caller.
<2> Parse the line, forward errors to the caller.

6
include/boost/leaf/all.hpp
View File

@@ -972,15 +972,15 @@ namespace boost { namespace leaf {
#define BOOST_LEAF_TOKEN_PASTE(x, y) x ## y
#define BOOST_LEAF_TOKEN_PASTE2(x, y) BOOST_LEAF_TOKEN_PASTE(x, y)
#define BOOST_LEAF_VAR(v,r)\
static_assert(::boost::leaf::is_result_type<typename std::decay<decltype(r)>::type>::value, "The BOOST_LEAF_VAR macro requires a result type as the second argument");\
#define BOOST_LEAF_ASSIGN(v,r)\
static_assert(::boost::leaf::is_result_type<typename std::decay<decltype(r)>::type>::value, "The BOOST_LEAF_ASSIGN macro requires a result type as the second argument");\
auto && BOOST_LEAF_TOKEN_PASTE2(boost_leaf_temp_, __LINE__) = r;\
if( !BOOST_LEAF_TOKEN_PASTE2(boost_leaf_temp_, __LINE__) )\
return BOOST_LEAF_TOKEN_PASTE2(boost_leaf_temp_, __LINE__).error();\
v = BOOST_LEAF_TOKEN_PASTE2(boost_leaf_temp_, __LINE__).value()
#define BOOST_LEAF_AUTO(v, r)\
BOOST_LEAF_VAR(auto && v, r)
BOOST_LEAF_ASSIGN(auto && v, r)
#define BOOST_LEAF_CHECK(r)\
{\

6
include/boost/leaf/error.hpp
View File

@@ -25,15 +25,15 @@
#define BOOST_LEAF_TOKEN_PASTE(x, y) x ## y
#define BOOST_LEAF_TOKEN_PASTE2(x, y) BOOST_LEAF_TOKEN_PASTE(x, y)
#define BOOST_LEAF_VAR(v,r)\
static_assert(::boost::leaf::is_result_type<typename std::decay<decltype(r)>::type>::value, "The BOOST_LEAF_VAR macro requires a result type as the second argument");\
#define BOOST_LEAF_ASSIGN(v,r)\
static_assert(::boost::leaf::is_result_type<typename std::decay<decltype(r)>::type>::value, "The BOOST_LEAF_ASSIGN macro requires a result type as the second argument");\
auto && BOOST_LEAF_TOKEN_PASTE2(boost_leaf_temp_, __LINE__) = r;\
if( !BOOST_LEAF_TOKEN_PASTE2(boost_leaf_temp_, __LINE__) )\
return BOOST_LEAF_TOKEN_PASTE2(boost_leaf_temp_, __LINE__).error();\
v = BOOST_LEAF_TOKEN_PASTE2(boost_leaf_temp_, __LINE__).value()
#define BOOST_LEAF_AUTO(v, r)\
BOOST_LEAF_VAR(auto && v, r)
BOOST_LEAF_ASSIGN(auto && v, r)
#define BOOST_LEAF_CHECK(r)\
{\

2
meson.build
View File

@@ -90,7 +90,7 @@ tests = [
'accumulate_nested_success_exception_test',
'accumulate_nested_success_result_test',
'BOOST_LEAF_AUTO_test',
'BOOST_LEAF_VAR_test',
'BOOST_LEAF_ASSIGN_test',
'capture_exception_async_test',
'capture_exception_result_async_test',
'capture_exception_state_test',

6
test/BOOST_LEAF_VAR_test.cpp → test/BOOST_LEAF_ASSIGN_test.cpp
View File

@@ -18,15 +18,15 @@ int main()
int x = 42;
leaf::result<int> r1(x);
BOOST_LEAF_VAR(auto && rx1, r1);
BOOST_LEAF_ASSIGN(auto && rx1, r1);
BOOST_TEST_EQ(r1.value(), rx1);
leaf::result<int &> r2(x);
BOOST_LEAF_VAR(auto && rx2, r2);
BOOST_LEAF_ASSIGN(auto && rx2, r2);
BOOST_TEST_EQ(r2.value(), rx2);
leaf::result<int &> r3(x);
BOOST_LEAF_VAR(auto & rx3, r3);
BOOST_LEAF_ASSIGN(auto & rx3, r3);
BOOST_TEST_EQ(&r3.value(), &rx3);
return 0;

2
test/Jamfile.v2
View File

@@ -39,7 +39,7 @@ run accumulate_nested_new_error_result_test.cpp ;
run accumulate_nested_success_exception_test.cpp ;
run accumulate_nested_success_result_test.cpp ;
run BOOST_LEAF_AUTO_test.cpp ;
run BOOST_LEAF_VAR_test.cpp ;
run BOOST_LEAF_ASSIGN_test.cpp ;
run boost_exception_test.cpp ;
run capture_exception_async_test.cpp ;
run capture_exception_result_async_test.cpp ;