Error: Variable "Cannot Be Implicitly Captured Because No Default Capture Mode Has Been Specified"

Error: variable cannot be implicitly captured because no default capture mode has been specified

You must specify flagId to be captured. That is what the [] part is for. Right now it doesn't capture anything. You can capture (more info) by value or by reference. Something like:

auto new_end = std::remove_if(m_FinalFlagsVec.begin(), m_FinalFlagsVec.end(),
        [&flagId](Flag& device)
    { return device.getId() == flagId; });

Which captures by reference. If you want to capture by const value, you can do this:

auto new_end = std::remove_if(m_FinalFlagsVec.begin(), m_FinalFlagsVec.end(),
        [flagId](Flag& device)
    { return device.getId() == flagId; });

Or by mutable value:

auto new_end = std::remove_if(m_FinalFlagsVec.begin(), m_FinalFlagsVec.end(),
        [flagId](Flag& device) mutable
    { return device.getId() == flagId; });

Sadly there is no straightforward way to capture by const reference until C++17. I personally would just declare a temporary const ref and capture that by ref:

const auto& tmp = flagId;
auto new_end = std::remove_if(m_FinalFlagsVec.begin(), m_FinalFlagsVec.end(),
            [&tmp](Flag& device)
        { return device.getId() == tmp; }); //tmp is immutable

In C++17 and beyond we can capture by const-reference by using as_const

auto new_end = std::remove_if(m_FinalFlagsVec.begin(), m_FinalFlagsVec.end(),
            [&flagId = std::as_const(flagId)](Flag& device)
        { return device.getId() == flagId; });

variable cannot be implicitly captured in a lambda with no capture-default specified using a switch statement

Lambdas have a closed scope. To access the parent's scope you need to specify the capture defaults & or = like so:

[&](char &c) {};
// or
[=](char &c) {};

From https://en.cppreference.com/w/cpp/language/lambda:

&: implicitly capture the used automatic variables by reference.

=: implicitly capture the used automatic variables by copy.

C++ Visual Studio error: Identifier cannot be implicitly captured because no default capture mode has been specified

You can't use surrounding variables in a lambda unless you capture them.

You use compFileName which is defined in the surrounding scope, but it's not listed as a capture.

Simple fix: Add &compFileName to your capture list:

[&file_name, &compFileName](const auto & dir_entry) { ... }

Even simpler: Capture all used variables:

[&](const auto & dir_entry) { ... }

Compiler error C3493: 'func' cannot be implicitly captured because no default capture mode has been specified

You need to specify how to capture func into the lambda.

[] don't capture anything

[&] capture-by-reference

[=] capture-by-value (copy)

T::ForEach([&](T *what) {

I'd also recommend that you should send func by const reference.

static void ComputeGenericDropCount(const function<void(Npc *, int)>& func)

Qt5 - C++11: 'This' cannot be implicitly captured in this context

Your lambda does not capture ui or this, so there's no way to call ui->textEditLidar->setText.

Change this

connect(this->executeROSLidarApp, &QProcess::errorOccurred, [script = this->executeROSLidarApp](QProcess::ProcessError error) {
        qDebug() << "[EXEC] error on execution: " << error << script->errorString();

        ui->textEditLidar->setText("would like to see the output of the error"); // <-- error here
});

to this

connect(this->executeROSLidarApp, &QProcess::errorOccurred, [this, script = this->executeROSLidarApp](QProcess::ProcessError error) {
        qDebug() << "[EXEC] error on execution: " << error << script->errorString();

        ui->textEditLidar->setText("would like to see the output of the error"); // <-- error here
});

or this

connect(this->executeROSLidarApp, &QProcess::errorOccurred, [ui, script = this->executeROSLidarApp](QProcess::ProcessError error) {
        qDebug() << "[EXEC] error on execution: " << error << script->errorString();

        ui->textEditLidar->setText("would like to see the output of the error"); // <-- error here
});

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